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add comments to elim_unconstr_tactic

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2022-11-10 16:42:09 -08:00
parent 15be80c954
commit 689af3b4df
1 changed files with 89 additions and 4 deletions
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93
src/tactic/core/elim_uncnstr_tactic.cpp
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@ -270,7 +270,36 @@ class elim_uncnstr_tactic : public tactic {
}
return nullptr;
}
/**
* if (c, x, x') -> fresh
* x := fresh
* x' := fresh
*
* if (x, x', e) -> fresh
* x := true
* x' := fresh
*
* if (x, t, x') -> fresh
* x := false
* x' := fresh
*
* not x -> fresh
* x := not fresh
*
* x & x' -> fresh
* x := fresh
* x' := true
*
* x or x' -> fresh
* x := fresh
* x' := false
*
* x = t -> fresh
* x := if(fresh, t, diff(t))
* where diff is a diagnonalization function available in domains of size > 1.
*
*/
app * process_basic_app(func_decl * f, unsigned num, expr * const * args) {
SASSERT(f->get_family_id() == m().get_basic_family_id());
switch (f->get_decl_kind()) {
@ -434,6 +463,10 @@ class elim_uncnstr_tactic : public tactic {
}
return nullptr;
}
/**
* similar as for bit-vectors
*/
app * process_arith_app(func_decl * f, unsigned num, expr * const * args) {
@ -466,7 +499,7 @@ class elim_uncnstr_tactic : public tactic {
add_defs(num, args, r, m_bv_util.mk_numeral(rational(1), s));
return r;
}
// c * v (c is even) case
// c * v (c is odd) case
unsigned bv_size;
rational val;
rational inv;
@ -595,7 +628,46 @@ class elim_uncnstr_tactic : public tactic {
}
return nullptr;
}
/**
* x + t -> fresh
* x := fresh - t
*
* x * x' * x'' -> fresh
* x := fresh
* x', x'' := 1
*
* c * x -> fresh, c is odd
* x := fresh*c^-1
*
* x[sz-1:0] -> fresh
* x := fresh
*
* x[hi:lo] -> fresh
* x := fresh1 ++ fresh ++ fresh2
*
* x udiv x', x sdiv x' -> fresh
* x' := 1
* x := fresh
*
* x ++ x' ++ x'' -> fresh
* x := fresh[hi1:lo1]
* x' := fresh[hi2:lo2]
* x'' := fresh[hi3:lo3]
*
* x <= t -> fresh or t == MAX
* x := if(fresh, t, t + 1)
* t <= x -> fresh or t == MIN
* x := if(fresh, t, t - 1)
*
* ~x -> fresh
* x := ~fresh
*
* x | y -> fresh
* x := fresh
* y := 0
*
*/
app * process_bv_app(func_decl * f, unsigned num, expr * const * args) {
SASSERT(f->get_family_id() == m_bv_util.get_family_id());
switch (f->get_decl_kind()) {
@ -646,6 +718,15 @@ class elim_uncnstr_tactic : public tactic {
return nullptr;
}
}
/**
* F[select(x, i)] -> F[fresh]
* x := const(fresh)
* F[store(x, ..., x')] -> F[fresh]
* x' := select(x, ...)
* x := fresh
*/
app * process_array_app(func_decl * f, unsigned num, expr * const * args) {
SASSERT(f->get_family_id() == m_ar_util.get_family_id());
@ -676,7 +757,11 @@ class elim_uncnstr_tactic : public tactic {
return nullptr;
}
}
/**
* head(x) -> fresh
* x := cons(fresh, arb)
*/
app * process_datatype_app(func_decl * f, unsigned num, expr * const * args) {
if (m_dt_util.is_accessor(f)) {
SASSERT(num == 1);