cave in to supporting proofs (partially) in simplifiers, updated doc

src/tactic/core/injectivity_tactic.cpp

@@ -5,19 +5,11 @@ Module Name:
 
   injectivity_tactic.cpp
 
-Abstract:
-
-  Injectivity tactics
-  - Discover axioms of the form `forall x. (= (g (f x)) x`
-    Mark `f` as injective
-  - Rewrite (sub)terms of the form `(= (f x) (f y))` to `(= x y)` whenever `f` is injective.
 
 Author:
 
   Nicolas Braud-Santoni (t-nibrau) 2017-08-10
 
-Notes:
-
 --*/
 #include <algorithm>
 #include <utility>
@@ -164,8 +156,6 @@ class injectivity_tactic : public tactic {
     struct rewriter_eq_cfg : public default_rewriter_cfg {
         ast_manager              & m_manager;
         InjHelper                & inj_map;
-//        expr_ref_vector            m_out;
-//        sort_ref_vector            m_bindings;
 
         ast_manager & m() const { return m_manager; }
 
@@ -176,14 +166,13 @@ class injectivity_tactic : public tactic {
         }
 
         void cleanup_buffers() {
-//            m_out.finalize();
         }
 
         void reset() {
         }
 
         br_status reduce_app(func_decl * f, unsigned num, expr * const * args, expr_ref & result, proof_ref & result_pr) {
-            if(num != 2)
+            if (num != 2)
                 return BR_FAILED;
 
             if (!m().is_eq(f))
@@ -230,8 +219,6 @@ class injectivity_tactic : public tactic {
     finder *           m_finder;
     rewriter_eq *      m_eq;
     InjHelper *        m_map;
-//    rewriter_inverse * m_inverse;
-
     params_ref         m_params;
     ast_manager &      m_manager;
 

src/tactic/core/injectivity_tactic.h

@@ -13,7 +13,33 @@ Author:
 
     Nicolas Braud-Santoni (t-nibrau) 2017-08-10
 
-Notes:
+
+Tactic Documentation:
+
+## Tactic injectivity
+
+### Short Description:
+
+- Discover axioms of the form `forall x. (= (g (f x)) x`
+  Mark `f` as injective
+
+- Rewrite (sub)terms of the form `(= (f x) (f y))` to `(= x y)` whenever `f` is injective.
+
+### Example
+ 
+```z3
+  (declare-fun f (Int) Int)
+  (declare-fun g (Int) Int)
+  (declare-const x Int)
+  (declare-const y Int)
+  (assert (forall ((x Int)) (= (g (f x)) x)))
+  (assert (not (= (f x) (f (f y)))))
+  (apply injectivity)
+```
+
+### Notes
+
+* does not support cores nor proofs
 
 --*/
 #pragma once

src/tactic/core/reduce_args_tactic.h

@@ -23,15 +23,15 @@ Reduce the number of arguments of function applications, when for all occurrence
 
 ### Long Description
 
-Example, suppose we have a function `f` with `2` arguments. 
-There are 1000 applications of this function, but the first argument is always "a", "b" or "c".
-Thus, we replace the `f(t1, t2)` with 
+Example, suppose we have a function $f$ with 2 arguments. 
+There are 1000 applications of this function, but the first argument is always $a$, $b$ or $c$.
+Thus, we replace the $f(t_1, t_2)$ with 
 
-*      `f_a(t2)`   if   `t1 = a`
-*      `f_b(t2)`   if   `t2 = b`
-*      `f_c(t2)`   if   `t2 = c`
+* $f_a(t_2)$   if   $t_1 = a$
+* $f_b(t_2)$   if   $t_2 = b$
+* $f_c(t_2)$   if   $t_2 = c$
 
-Since `f_a`, `f_b`, `f_c` are new symbols, satisfiability is preserved.
+Since $f_a$, $f_b$, $f_c$ are new symbols, satisfiability is preserved.
    
 This transformation is very similar in spirit to the Ackermman's reduction.