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			762 lines
		
	
	
	
		
			29 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*++
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Copyright (c) 2012 Microsoft Corporation
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Module Name:
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    nlsat_interval_set.cpp
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Abstract:
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    Sets of disjoint infeasible intervals.
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Author:
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    Leonardo de Moura (leonardo) 2012-01-11.
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Revision History:
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--*/
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#include"nlsat_interval_set.h"
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#include"algebraic_numbers.h"
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#include"buffer.h"
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namespace nlsat {
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    struct interval {
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        unsigned  m_lower_open:1;
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        unsigned  m_upper_open:1;
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        unsigned  m_lower_inf:1;
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        unsigned  m_upper_inf:1;
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        literal   m_justification;
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        anum      m_lower;
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        anum      m_upper;
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    };
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    class interval_set {
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    public:
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        static unsigned get_obj_size(unsigned num) { return sizeof(interval_set) + num*sizeof(interval); }
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        unsigned  m_num_intervals;
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        unsigned  m_ref_count:31;
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        unsigned  m_full:1;
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        interval  m_intervals[0];
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    };
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    void display(std::ostream & out, anum_manager & am, interval const & curr) {
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        if (curr.m_lower_inf) {
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            out << "(-oo, ";
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        }
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        else {
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            if (curr.m_lower_open)
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                    out << "(";
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            else
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                out << "[";
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            am.display_decimal(out, curr.m_lower);
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            out << ", ";
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        }
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        if (curr.m_justification.sign())
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            out << "~";
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        out << "p";
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        out << curr.m_justification.var() << ", ";
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        if (curr.m_upper_inf) {
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            out << "oo)";
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        }
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        else {
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            am.display_decimal(out, curr.m_upper);
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            if (curr.m_upper_open)
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                out << ")";
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            else
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                out << "]";
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        }
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    }
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    bool check_interval(anum_manager & am, interval const & i) {
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        if (i.m_lower_inf) {
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            SASSERT(i.m_lower_open);
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        }
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        if (i.m_upper_inf) {
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            SASSERT(i.m_upper_open);
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        }
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        if (!i.m_lower_inf && !i.m_upper_inf) {
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            int s = am.compare(i.m_lower, i.m_upper);
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            TRACE("nlsat_interval", tout << "lower: "; am.display_decimal(tout, i.m_lower); tout << ", upper: "; am.display_decimal(tout, i.m_upper);
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                  tout << "\ns: " << s << "\n";);
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            SASSERT(s <= 0);
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            if (s == 0) {
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                SASSERT(!i.m_lower_open && !i.m_upper_open);
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            }
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        }
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        return true;
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    }
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    bool check_no_overlap(anum_manager & am, interval const & curr, interval const & next) {
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        SASSERT(!curr.m_upper_inf);
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        SASSERT(!next.m_lower_inf);
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        int sign = am.compare(curr.m_upper, next.m_lower);
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        CTRACE("nlsat", sign > 0, display(tout, am, curr); tout << "  "; display(tout, am, next); tout << "\n";);
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        SASSERT(sign <= 0);
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        if (sign == 0) {
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            SASSERT(curr.m_upper_open || next.m_lower_open);
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        }
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        return true;
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    }
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    // Check if the intervals are valid, ordered, and are disjoint.
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    bool check_interval_set(anum_manager & am, unsigned sz, interval const * ints) {
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        DEBUG_CODE(
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            for (unsigned i = 0; i < sz; i++) {
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                interval const & curr = ints[i];
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                SASSERT(check_interval(am, curr));
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                if (i < sz - 1) {
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                    SASSERT(check_no_overlap(am, curr, ints[i+1]));
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                }
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            });
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        return true;
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    }
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    interval_set_manager::interval_set_manager(anum_manager & m, small_object_allocator & a):
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        m_am(m),
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        m_allocator(a) {
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    }
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    interval_set_manager::~interval_set_manager() {
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    }
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    void interval_set_manager::del(interval_set * s) {
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        if (s == 0)
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            return;
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        unsigned num    = s->m_num_intervals;
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        unsigned obj_sz = interval_set::get_obj_size(num);
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        for (unsigned i = 0; i < num; i++) {
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            m_am.del(s->m_intervals[i].m_lower);
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            m_am.del(s->m_intervals[i].m_upper);
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        }
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        s->~interval_set();
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        m_allocator.deallocate(obj_sz, s);
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    }
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    void interval_set_manager::dec_ref(interval_set * s) {
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        SASSERT(s->m_ref_count > 0);
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        s->m_ref_count--;
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        if (s->m_ref_count == 0)
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            del(s);
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    }
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    void interval_set_manager::inc_ref(interval_set * s) {
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        s->m_ref_count++;
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    }
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    interval_set * interval_set_manager::mk(bool lower_open, bool lower_inf, anum const & lower, 
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                                            bool upper_open, bool upper_inf, anum const & upper,
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                                            literal justification) {
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        void * mem = m_allocator.allocate(interval_set::get_obj_size(1));
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        interval_set * new_set = new (mem) interval_set();
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        new_set->m_num_intervals = 1;
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        new_set->m_ref_count  = 0;
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        new_set->m_full       = lower_inf && upper_inf;
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        interval * i = new (new_set->m_intervals) interval();
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        i->m_lower_open = lower_open;
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        i->m_lower_inf  = lower_inf;
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        i->m_upper_open = upper_open;
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        i->m_upper_inf  = upper_inf;
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        i->m_justification = justification;
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        if (!lower_inf)
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            m_am.set(i->m_lower, lower);
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        if (!upper_inf)
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            m_am.set(i->m_upper, upper);
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        SASSERT(check_interval_set(m_am, 1, new_set->m_intervals));
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        return new_set;
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    }
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    inline int compare_lower_lower(anum_manager & am, interval const & i1, interval const & i2) {
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        if (i1.m_lower_inf && i2.m_lower_inf)
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            return 0;
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        if (i1.m_lower_inf)
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            return -1;
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        if (i2.m_lower_inf)
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            return 1;
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        SASSERT(!i1.m_lower_inf && !i2.m_lower_inf);
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        int s = am.compare(i1.m_lower, i2.m_lower);
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        if (s != 0)
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            return s;
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        if (i1.m_lower_open == i2.m_lower_open)
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            return 0;
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        if (i1.m_lower_open)
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            return 1;
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        else
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            return -1;
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    }
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    inline int compare_upper_upper(anum_manager & am, interval const & i1, interval const & i2) {
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        if (i1.m_upper_inf && i2.m_upper_inf)
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            return 0;
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        if (i1.m_upper_inf)
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            return 1;
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        if (i2.m_upper_inf)
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            return -1;
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        SASSERT(!i1.m_upper_inf && !i2.m_upper_inf);
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        int s = am.compare(i1.m_upper, i2.m_upper);
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        if (s != 0)
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            return s;
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        if (i1.m_upper_open == i2.m_upper_open)
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            return 0;
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        if (i1.m_upper_open)
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            return -1;
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        else
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            return 1;
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    }
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    inline int compare_upper_lower(anum_manager & am, interval const & i1, interval const & i2) {
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        if (i1.m_upper_inf || i2.m_lower_inf)
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            return 1;
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        SASSERT(!i1.m_upper_inf && !i2.m_lower_inf);
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        int s = am.compare(i1.m_upper, i2.m_lower);
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        if (s != 0)
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            return s;
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        if (!i1.m_upper_open && !i2.m_lower_open)
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            return 0;
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        return -1;
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    }
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    typedef sbuffer<interval, 128> interval_buffer;
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    // Given two interval in an interval set s.t. curr occurs before next.
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    // We say curr and next are "adjacent" iff
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    //      there is no "space" between them.
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    bool adjacent(anum_manager & am, interval const & curr, interval const & next) {
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        SASSERT(!curr.m_upper_inf);
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        SASSERT(!next.m_lower_inf);
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        int sign = am.compare(curr.m_upper, next.m_lower);
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        SASSERT(sign <= 0);
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        if (sign == 0) {
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            SASSERT(curr.m_upper_open || next.m_lower_open);
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            return !curr.m_upper_open || !next.m_lower_open;
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        }
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        return false;
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    }
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    inline void push_back(anum_manager & am, interval_buffer & buf, 
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                          bool lower_open, bool lower_inf, anum const & lower, 
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                          bool upper_open, bool upper_inf, anum const & upper,
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                          literal justification) {
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        buf.push_back(interval());
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        interval & i = buf.back();
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        i.m_lower_open = lower_open;
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        i.m_lower_inf  = lower_inf;
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        am.set(i.m_lower, lower);
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        i.m_upper_open = upper_open;
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        i.m_upper_inf  = upper_inf;
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        am.set(i.m_upper, upper);
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        i.m_justification = justification;
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        SASSERT(check_interval(am, i));
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    }
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    inline void push_back(anum_manager & am, interval_buffer & buf, interval const & i) {
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        push_back(am, buf,
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                  i.m_lower_open, i.m_lower_inf, i.m_lower,
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                  i.m_upper_open, i.m_upper_inf, i.m_upper,
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                  i.m_justification);
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    }
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    inline interval_set * mk_interval(small_object_allocator & allocator, interval_buffer & buf, bool full) {
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        unsigned sz = buf.size();
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        void * mem = allocator.allocate(interval_set::get_obj_size(sz));
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        interval_set * new_set = new (mem) interval_set();
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        new_set->m_full = full;
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        new_set->m_ref_count  = 0;
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        new_set->m_num_intervals = sz;
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        memcpy(new_set->m_intervals, buf.c_ptr(), sizeof(interval)*sz);
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        return new_set;
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    }
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    interval_set * interval_set_manager::mk_union(interval_set const * s1, interval_set const * s2) {
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        TRACE("nlsat_interval", tout << "mk_union\ns1: "; display(tout, s1); tout << "\ns2: "; display(tout, s2); tout << "\n";);
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        if (s1 == 0 || s1 == s2)
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            return const_cast<interval_set*>(s2);
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        if (s2 == 0)
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            return const_cast<interval_set*>(s1);
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        if (s1->m_full)
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            return const_cast<interval_set*>(s1);
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        if (s2->m_full)
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            return const_cast<interval_set*>(s2);
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        interval_buffer result;
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        unsigned sz1 = s1->m_num_intervals;
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        unsigned sz2 = s2->m_num_intervals;
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        unsigned i1  = 0;
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        unsigned i2  = 0;
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        while (true) {
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            if (i1 >= sz1) {
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                while (i2 < sz2) {
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                    TRACE("nlsat_interval", tout << "adding remaining intervals from s2: "; nlsat::display(tout, m_am, s2->m_intervals[i2]); tout << "\n";);
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                    push_back(m_am, result, s2->m_intervals[i2]);
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                    i2++;
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                }
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                break;
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            }
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            if (i2 >= sz2) {
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                while (i1 < sz1) {
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                    TRACE("nlsat_interval", tout << "adding remaining intervals from s1: "; nlsat::display(tout, m_am, s1->m_intervals[i1]); tout << "\n";);
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                    push_back(m_am, result, s1->m_intervals[i1]);
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                    i1++;
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                }
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                break;
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            }
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            interval const & int1 = s1->m_intervals[i1];
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            interval const & int2 = s2->m_intervals[i2];
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            int l1_l2_sign = compare_lower_lower(m_am, int1, int2);
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            int u1_u2_sign = compare_upper_upper(m_am, int1, int2);
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            TRACE("nlsat_interval", 
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                  tout << "i1: " << i1 << ", i2: " << i2 << "\n";
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                  tout << "int1: "; nlsat::display(tout, m_am, int1); tout << "\n";
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                  tout << "int2: "; nlsat::display(tout, m_am, int2); tout << "\n";);
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            if (l1_l2_sign <= 0) {
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                if (u1_u2_sign == 0) {
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                    // Cases:
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                    // 1)  [     ]
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                    //     [     ]
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                    //
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                    // 2) [     ]
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                    //      [   ]
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                    //
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                    TRACE("nlsat_interval", tout << "l1_l2_sign <= 0, u1_u2_sign == 0\n";);
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                    push_back(m_am, result, int1);
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                    i1++;
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                    i2++;
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                }
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                else if (u1_u2_sign > 0) {
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                    // Cases:
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                    //
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                    // 1) [        ]
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                    //    [     ]
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                    //
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                    // 2) [        ]
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                    //      [   ]
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                    i2++;
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                    TRACE("nlsat_interval", tout << "l1_l2_sign <= 0, u1_u2_sign > 0\n";);
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                    // i1 may consume other intervals of s2
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                }
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                else {
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                    SASSERT(u1_u2_sign < 0);
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                    int u1_l2_sign = compare_upper_lower(m_am, int1, int2);
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                    if (u1_l2_sign < 0) {
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                        SASSERT(l1_l2_sign < 0);
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                        // Cases:
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                        // 1)   [      ]
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                        //                [     ]
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                        TRACE("nlsat_interval", tout << "l1_l2_sign <= 0, u1_u2_sign < 0, u1_l2_sign < 0\n";);
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                        push_back(m_am, result, int1);
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                        i1++;
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                    }
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                    else if (u1_l2_sign == 0) {
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                        SASSERT(l1_l2_sign <= 0);
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                        SASSERT(!int1.m_upper_open && !int2.m_lower_open);
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                        SASSERT(!int2.m_lower_inf);
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                        TRACE("nlsat_interval", tout << "l1_l2_sign <= 0, u1_u2_sign < 0, u1_l2_sign == 0\n";);
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                        // Cases:
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                        if (l1_l2_sign != 0) {
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                            SASSERT(l1_l2_sign < 0);
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                            // 1)   [   ]
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                            //          [    ]
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                            SASSERT(!int2.m_lower_open);
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                            push_back(m_am, result, 
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                                      int1.m_lower_open, int1.m_lower_inf,  int1.m_lower,
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                                      true /* open */, false /* not +oo */, int1.m_upper, 
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                                      int1.m_justification); 
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                            i1++;
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                        }
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                        else {
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                            SASSERT(l1_l2_sign == 0);
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                            // 2)   u          <<< int1 is a singleton
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                            //      [     ]
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                            // just consume int1
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                            i1++;
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                        }
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                    }
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                    else {
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                        SASSERT(l1_l2_sign <= 0);
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                        SASSERT(u1_u2_sign < 0);
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                        SASSERT(u1_l2_sign > 0);
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                        TRACE("nlsat_interval", tout << "l1_l2_sign <= 0, u1_u2_sign < 0, u1_l2_sign > 0\n";);
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                        if (l1_l2_sign == 0) {
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                            // Case:
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                            // 1)   [      ]
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                            //      [          ]
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                            // just consume int1
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                            i1++;
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                        }
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                        else {
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                            SASSERT(l1_l2_sign < 0);
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                            SASSERT(u1_u2_sign < 0);
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                            SASSERT(u1_l2_sign > 0);
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                            // 2) [        ]
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                            //         [        ]
 | 
						|
                            push_back(m_am, result, 
 | 
						|
                                      int1.m_lower_open,     int1.m_lower_inf, int1.m_lower,
 | 
						|
                                      !int2.m_lower_open, false /* not +oo */, int2.m_lower,
 | 
						|
                                      int1.m_justification); 
 | 
						|
                            i1++;
 | 
						|
                        }
 | 
						|
                    }
 | 
						|
                }
 | 
						|
            }
 | 
						|
            else {
 | 
						|
                SASSERT(l1_l2_sign > 0);
 | 
						|
                if (u1_u2_sign == 0) {
 | 
						|
                    TRACE("nlsat_interval", tout << "l1_l2_sign > 0, u1_u2_sign == 0\n";);
 | 
						|
                    // Case:
 | 
						|
                    // 1)    [  ]
 | 
						|
                    //    [     ]
 | 
						|
                    //
 | 
						|
                    push_back(m_am, result, int2);
 | 
						|
                    i1++;
 | 
						|
                    i2++;
 | 
						|
                }
 | 
						|
                else if (u1_u2_sign < 0) {
 | 
						|
                    TRACE("nlsat_interval", tout << "l1_l2_sign > 0, u1_u2_sign > 0\n";);
 | 
						|
                    // Case:
 | 
						|
                    // 1)   [   ]
 | 
						|
                    //    [       ]
 | 
						|
                    i1++;
 | 
						|
                    // i2 may consume other intervals of s1
 | 
						|
                }
 | 
						|
                else {
 | 
						|
                    int u2_l1_sign = compare_upper_lower(m_am, int2, int1);
 | 
						|
                    if (u2_l1_sign < 0) {
 | 
						|
                        TRACE("nlsat_interval", tout << "l1_l2_sign > 0, u1_u2_sign > 0, u2_l1_sign < 0\n";);
 | 
						|
                        // Case:
 | 
						|
                        // 1)           [      ]
 | 
						|
                        //     [     ]
 | 
						|
                        push_back(m_am, result, int2);
 | 
						|
                        i2++;
 | 
						|
                    }
 | 
						|
                    else if (u2_l1_sign == 0) {
 | 
						|
                        TRACE("nlsat_interval", tout << "l1_l2_sign > 0, u1_u2_sign > 0, u2_l1_sign == 0\n";);
 | 
						|
                        SASSERT(!int1.m_lower_open && !int2.m_upper_open);
 | 
						|
                        SASSERT(!int1.m_lower_inf);
 | 
						|
                        // Case:
 | 
						|
                        //      [    ]   
 | 
						|
                        //  [   ]
 | 
						|
                        push_back(m_am, result, 
 | 
						|
                                  int2.m_lower_open,     int2.m_lower_inf, int2.m_lower,
 | 
						|
                                  true /* open */,    false /* not +oo */, int2.m_upper, 
 | 
						|
                                  int2.m_justification); 
 | 
						|
                        i2++;
 | 
						|
                    }
 | 
						|
                    else {
 | 
						|
                        TRACE("nlsat_interval", tout << "l1_l2_sign > 0, u1_u2_sign > 0, u2_l1_sign > 0\n";);
 | 
						|
                        SASSERT(l1_l2_sign > 0);
 | 
						|
                        SASSERT(u1_u2_sign > 0);
 | 
						|
                        SASSERT(u2_l1_sign > 0);
 | 
						|
                        // Case:
 | 
						|
                        //     [        ]
 | 
						|
                        // [        ]
 | 
						|
                        push_back(m_am, result, 
 | 
						|
                                  int2.m_lower_open,     int2.m_lower_inf, int2.m_lower,
 | 
						|
                                  !int1.m_lower_open, false /* not +oo */, int1.m_lower,
 | 
						|
                                  int2.m_justification); 
 | 
						|
                        i2++;
 | 
						|
                    }
 | 
						|
                }
 | 
						|
            }
 | 
						|
            SASSERT(result.size() <= 1 ||
 | 
						|
                    check_no_overlap(m_am, result[result.size() - 2], result[result.size() - 1]));
 | 
						|
        }
 | 
						|
 | 
						|
        SASSERT(!result.empty());
 | 
						|
        SASSERT(check_interval_set(m_am, result.size(), result.c_ptr()));
 | 
						|
        // Compress
 | 
						|
        // Remark: we only combine adjacent intervals when they have the same justification
 | 
						|
        unsigned j  = 0;
 | 
						|
        unsigned sz = result.size(); 
 | 
						|
        for (unsigned i = 1; i < sz; i++) {
 | 
						|
            interval & curr = result[j];
 | 
						|
            interval & next = result[i];
 | 
						|
            if (curr.m_justification == next.m_justification && 
 | 
						|
                adjacent(m_am, curr, next)) {
 | 
						|
                // merge them
 | 
						|
                curr.m_upper_inf  = next.m_upper_inf;
 | 
						|
                curr.m_upper_open = next.m_upper_open;
 | 
						|
                m_am.swap(curr.m_upper, next.m_upper);
 | 
						|
            }
 | 
						|
            else {
 | 
						|
                j++;
 | 
						|
                if (i != j) {
 | 
						|
                    interval & next_curr = result[j];
 | 
						|
                    next_curr.m_lower_inf = next.m_lower_inf;
 | 
						|
                    next_curr.m_lower_open = next.m_lower_open;
 | 
						|
                    m_am.swap(next_curr.m_lower, next.m_lower);
 | 
						|
                    next_curr.m_upper_inf = next.m_upper_inf;
 | 
						|
                    next_curr.m_upper_open = next.m_upper_open;
 | 
						|
                    m_am.swap(next_curr.m_upper, next.m_upper);
 | 
						|
                    next_curr.m_justification = next.m_justification;
 | 
						|
                }
 | 
						|
            }
 | 
						|
        }
 | 
						|
        j++;
 | 
						|
        for (unsigned i = j; i < sz; i++) {
 | 
						|
            interval & curr = result[i];
 | 
						|
            m_am.del(curr.m_lower);
 | 
						|
            m_am.del(curr.m_upper);
 | 
						|
        }
 | 
						|
        result.shrink(j);
 | 
						|
        SASSERT(check_interval_set(m_am, result.size(), result.c_ptr()));
 | 
						|
        sz = j;
 | 
						|
        SASSERT(sz >= 1);
 | 
						|
        bool found_slack  = !result[0].m_lower_inf || !result[sz-1].m_upper_inf;
 | 
						|
        // Check if full
 | 
						|
        for (unsigned i = 0; i < sz - 1 && !found_slack; i++) {
 | 
						|
            if (!adjacent(m_am, result[i], result[i+1]))
 | 
						|
                found_slack = true;
 | 
						|
        }
 | 
						|
        // Create new interval set
 | 
						|
        interval_set * new_set = mk_interval(m_allocator, result, !found_slack);
 | 
						|
        SASSERT(check_interval_set(m_am, sz, new_set->m_intervals));
 | 
						|
        return new_set;
 | 
						|
    }
 | 
						|
 | 
						|
    bool interval_set_manager::is_full(interval_set const * s) {
 | 
						|
        if (s == 0)
 | 
						|
            return false;
 | 
						|
        return s->m_full == 1;
 | 
						|
    }
 | 
						|
 | 
						|
    unsigned interval_set_manager::num_intervals(interval_set const * s) const {
 | 
						|
        if (s == 0) return 0;
 | 
						|
        return s->m_num_intervals;
 | 
						|
    }
 | 
						|
    
 | 
						|
    bool interval_set_manager::subset(interval_set const * s1, interval_set const * s2) {
 | 
						|
        if (s1 == s2)
 | 
						|
            return true;
 | 
						|
        if (s1 == 0)
 | 
						|
            return true;
 | 
						|
        if (s2 == 0)
 | 
						|
            return false;
 | 
						|
        if (s2->m_full)
 | 
						|
            return true;
 | 
						|
        if (s1->m_full)
 | 
						|
            return false;
 | 
						|
        unsigned sz1 = s1->m_num_intervals;
 | 
						|
        unsigned sz2 = s2->m_num_intervals;
 | 
						|
        SASSERT(sz1 > 0 && sz2 > 0);
 | 
						|
        unsigned i1  = 0;
 | 
						|
        unsigned i2  = 0;
 | 
						|
        while (i1 < sz1 && i2 < sz2) {
 | 
						|
            interval const & int1 = s1->m_intervals[i1];
 | 
						|
            interval const & int2 = s2->m_intervals[i2];
 | 
						|
            TRACE("nlsat_interval", tout << "subset main loop, i1: " << i1 << ", i2: " << i2 << "\n";
 | 
						|
                  tout << "int1: "; nlsat::display(tout, m_am, int1); tout << "\n";
 | 
						|
                  tout << "int2: "; nlsat::display(tout, m_am, int2); tout << "\n";);
 | 
						|
            if (compare_lower_lower(m_am, int1, int2) < 0) {
 | 
						|
                TRACE("nlsat_interval", tout << "done\n";);
 | 
						|
                // interval [int1.lower1, int2.lower2] is not in s2
 | 
						|
                // s1: [ ...
 | 
						|
                // s2:    [ ...
 | 
						|
                return false;
 | 
						|
            }
 | 
						|
            while (i2 < sz2) {
 | 
						|
                interval const & int2 = s2->m_intervals[i2];
 | 
						|
                TRACE("nlsat_interval", tout << "inner loop, i2: " << i2 << "\n";
 | 
						|
                      tout << "int2: "; nlsat::display(tout, m_am, int2); tout << "\n";);
 | 
						|
                int u1_u2_sign = compare_upper_upper(m_am, int1, int2);
 | 
						|
                if (u1_u2_sign == 0) {
 | 
						|
                    TRACE("nlsat_interval", tout << "case 1, break\n";);
 | 
						|
                    // consume both
 | 
						|
                    // s1: ... ]
 | 
						|
                    // s2: ... ]
 | 
						|
                    i1++;
 | 
						|
                    i2++;
 | 
						|
                    break;
 | 
						|
                }
 | 
						|
                else if (u1_u2_sign < 0) {
 | 
						|
                    TRACE("nlsat_interval", tout << "case 2, break\n";);
 | 
						|
                    // consume only int1, int2 may cover other intervals of s1 
 | 
						|
                    // s1:  ... ]
 | 
						|
                    // s2:    ... ]
 | 
						|
                    i1++;
 | 
						|
                    break;
 | 
						|
                }
 | 
						|
                else {
 | 
						|
                    SASSERT(u1_u2_sign > 0);
 | 
						|
                    int u2_l1_sign = compare_upper_lower(m_am, int2, int1);
 | 
						|
                    TRACE("nlsat_interval", tout << "subset, u2_l1_sign: " << u2_l1_sign << "\n";);
 | 
						|
                    if (u2_l1_sign < 0) {
 | 
						|
                        TRACE("nlsat_interval", tout << "case 3, break\n";);
 | 
						|
                        // s1:           [ ...
 | 
						|
                        // s2: [ ... ]  ...
 | 
						|
                        i2++;
 | 
						|
                        break;
 | 
						|
                    }
 | 
						|
                    SASSERT(u2_l1_sign >= 0);
 | 
						|
                    // s1:      [ ...  ]
 | 
						|
                    // s2: [ ...    ]
 | 
						|
                    if (i2 == sz2 - 1) {
 | 
						|
                        TRACE("nlsat_interval", tout << "case 4, done\n";);
 | 
						|
                        // s1:   ... ]
 | 
						|
                        // s2: ...]
 | 
						|
                        // the interval [int2.upper, int1.upper] is not in s2
 | 
						|
                        return false; // last interval of s2
 | 
						|
                    }
 | 
						|
                    interval const & next2 = s2->m_intervals[i2+1];
 | 
						|
                    if (!adjacent(m_am, int2, next2)) {
 | 
						|
                        TRACE("nlsat_interval", tout << "not adjacent, done\n";);
 | 
						|
                        // s1:   ... ]
 | 
						|
                        // s2: ... ]   [
 | 
						|
                        // the interval [int2.upper, min(int1.upper, next2.lower)] is not in s2
 | 
						|
                        return false;
 | 
						|
                    }
 | 
						|
                    TRACE("nlsat_interval", tout << "continue..\n";);
 | 
						|
                    // continue with adjacent interval of s2
 | 
						|
                    // s1:    ...  ]
 | 
						|
                    // s2:  ..][ ...
 | 
						|
                    i2++;
 | 
						|
                }
 | 
						|
            }
 | 
						|
        }
 | 
						|
        return i1 == sz1;
 | 
						|
    }
 | 
						|
 | 
						|
    bool interval_set_manager::set_eq(interval_set const * s1, interval_set const * s2) {
 | 
						|
        if (s1 == 0 || s2 == 0)
 | 
						|
            return s1 == s2;
 | 
						|
        if (s1->m_full || s2->m_full)
 | 
						|
            return s1->m_full == s2->m_full;
 | 
						|
        // TODO: check if bottleneck, then replace simple implementation
 | 
						|
        return subset(s1, s2) && subset(s2, s1);
 | 
						|
    }
 | 
						|
        
 | 
						|
    bool interval_set_manager::eq(interval_set const * s1, interval_set const * s2) {
 | 
						|
        if (s1 == 0 || s2 == 0)
 | 
						|
            return s1 == s2;
 | 
						|
        if (s1->m_num_intervals != s2->m_num_intervals)
 | 
						|
            return false;
 | 
						|
        for (unsigned i = 0; i < s1->m_num_intervals; i++) {
 | 
						|
            interval const & int1 = s1->m_intervals[i];
 | 
						|
            interval const & int2 = s2->m_intervals[i]; 
 | 
						|
            if (int1.m_lower_inf  != int2.m_lower_inf ||
 | 
						|
                int1.m_lower_open != int2.m_lower_open ||
 | 
						|
                int1.m_upper_inf  != int2.m_upper_inf ||
 | 
						|
                int1.m_upper_open != int2.m_upper_open ||
 | 
						|
                int1.m_justification != int2.m_justification ||
 | 
						|
                !m_am.eq(int1.m_lower, int2.m_lower) ||
 | 
						|
                !m_am.eq(int1.m_upper, int2.m_upper))
 | 
						|
                return false;
 | 
						|
        }
 | 
						|
        return true;
 | 
						|
    }
 | 
						|
 | 
						|
    void interval_set_manager::get_justifications(interval_set const * s, literal_vector & js) {
 | 
						|
        js.reset();
 | 
						|
        unsigned num = num_intervals(s);
 | 
						|
        for (unsigned i = 0; i < num; i++) {
 | 
						|
            literal l     = s->m_intervals[i].m_justification;
 | 
						|
            unsigned lidx = l.index();
 | 
						|
            if (m_already_visited.get(lidx, false))
 | 
						|
                continue;
 | 
						|
            m_already_visited.setx(lidx, true, false);
 | 
						|
            js.push_back(l);
 | 
						|
        }
 | 
						|
        for (unsigned i = 0; i < num; i++) {
 | 
						|
            literal l     = s->m_intervals[i].m_justification;
 | 
						|
            unsigned lidx = l.index();
 | 
						|
            m_already_visited[lidx] = false;
 | 
						|
        }
 | 
						|
    }
 | 
						|
    
 | 
						|
    interval_set * interval_set_manager::get_interval(interval_set const * s, unsigned idx) const {
 | 
						|
        SASSERT(idx < num_intervals(s));
 | 
						|
        interval_buffer result;
 | 
						|
        push_back(m_am, result, s->m_intervals[idx]);
 | 
						|
        bool found_slack  = !result[0].m_lower_inf || !result[0].m_upper_inf;
 | 
						|
        interval_set * new_set = mk_interval(m_allocator, result, !found_slack);
 | 
						|
        SASSERT(check_interval_set(m_am, result.size(), new_set->m_intervals));
 | 
						|
        return new_set;
 | 
						|
    }
 | 
						|
 | 
						|
    void interval_set_manager::peek_in_complement(interval_set const * s, anum & w, bool randomize) {
 | 
						|
        SASSERT(!is_full(s));
 | 
						|
        if (s == 0) {
 | 
						|
            if (randomize) {
 | 
						|
                int num = m_rand() % 2 == 0 ? 1 : -1;
 | 
						|
#define MAX_RANDOM_DEN_K 4
 | 
						|
                int den_k = (m_rand() % MAX_RANDOM_DEN_K);
 | 
						|
                int den   = 1 << den_k;
 | 
						|
                scoped_mpq _w(m_am.qm());
 | 
						|
                m_am.qm().set(_w, num, den);
 | 
						|
                m_am.set(w, _w);
 | 
						|
                return;
 | 
						|
            }
 | 
						|
            else {
 | 
						|
                m_am.set(w, 0);
 | 
						|
                return;
 | 
						|
            }
 | 
						|
        }
 | 
						|
        
 | 
						|
        unsigned n = 0;
 | 
						|
        
 | 
						|
        unsigned num = num_intervals(s);
 | 
						|
        if (!s->m_intervals[0].m_lower_inf) {
 | 
						|
            // lower is not -oo
 | 
						|
            n++;
 | 
						|
            m_am.int_lt(s->m_intervals[0].m_lower, w);
 | 
						|
            if (!randomize)
 | 
						|
                return;
 | 
						|
        }
 | 
						|
        if (!s->m_intervals[num-1].m_upper_inf) {
 | 
						|
            // upper is not oo
 | 
						|
            n++;
 | 
						|
            if (n == 1 || m_rand()%n == 0)
 | 
						|
                m_am.int_gt(s->m_intervals[num-1].m_upper, w);
 | 
						|
            if (!randomize)
 | 
						|
                return;
 | 
						|
        }
 | 
						|
        
 | 
						|
        // Try to find a gap that is not an unit.
 | 
						|
        for (unsigned i = 1; i < num; i++) {
 | 
						|
            if (m_am.lt(s->m_intervals[i-1].m_upper, s->m_intervals[i].m_lower)) {
 | 
						|
                n++;
 | 
						|
                if (n == 1 || m_rand()%n == 0)
 | 
						|
                    m_am.select(s->m_intervals[i-1].m_upper, s->m_intervals[i].m_lower, w);
 | 
						|
                if (!randomize)
 | 
						|
                    return;
 | 
						|
            }
 | 
						|
        }
 | 
						|
        
 | 
						|
        if (n > 0)
 | 
						|
            return;
 | 
						|
        
 | 
						|
        // Try to find a rational
 | 
						|
        unsigned irrational_i = UINT_MAX;
 | 
						|
        for (unsigned i = 1; i < num; i++) {
 | 
						|
            if (s->m_intervals[i-1].m_upper_open && s->m_intervals[i].m_lower_open) {
 | 
						|
                SASSERT(m_am.eq(s->m_intervals[i-1].m_upper, s->m_intervals[i].m_lower)); // otherwise we would have found it in the previous step
 | 
						|
                if (m_am.is_rational(s->m_intervals[i-1].m_upper)) {
 | 
						|
                    m_am.set(w, s->m_intervals[i-1].m_upper);
 | 
						|
                    return;
 | 
						|
                }
 | 
						|
                if (irrational_i == UINT_MAX)
 | 
						|
                    irrational_i = i-1;
 | 
						|
            }
 | 
						|
        }
 | 
						|
        SASSERT(irrational_i != UINT_MAX);
 | 
						|
        // Last option: peek irrational witness :-(
 | 
						|
        SASSERT(s->m_intervals[irrational_i].m_upper_open && s->m_intervals[irrational_i+1].m_lower_open);
 | 
						|
        m_am.set(w, s->m_intervals[irrational_i].m_upper);
 | 
						|
    }
 | 
						|
 | 
						|
    void interval_set_manager::display(std::ostream & out, interval_set const * s) const {
 | 
						|
        if (s == 0) {
 | 
						|
            out << "{}";
 | 
						|
            return;
 | 
						|
        }
 | 
						|
        out << "{";
 | 
						|
        for (unsigned i = 0; i < s->m_num_intervals; i++) {
 | 
						|
            if (i > 0)
 | 
						|
                out << ", ";
 | 
						|
            nlsat::display(out, m_am, s->m_intervals[i]);
 | 
						|
        }
 | 
						|
        out << "}";
 | 
						|
        if (s->m_full)
 | 
						|
            out << "*";
 | 
						|
    }
 | 
						|
 | 
						|
};
 |