Fix to issue #1360: enable logic_simplify(), and add it to ATAlgEquiv.

maths · Jan 16, 2025 · eb775f1 · eb775f1
1 parent d224f5c
commit eb775f1
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Showing 3 changed files with 8 additions and 5 deletions.
diff --git a/stack/maxima/assessment.mac b/stack/maxima/assessment.mac
@@ -1299,13 +1299,14 @@ logical_normal(ex):=block(
     /* Change the noun logical operators into associative indenpotent ones. */
     ex:abs_replace_eq(ex),
     ex:boolean_form(ex),
-    ex:subst("%and", "nounand", ex),
-    ex:subst("%or", "nounor", ex),
-    /* %not is not an infix operator... */
-    ex:subst(%not, "not", ex),
-    ex:subst(%not, "nounnot", ex),
+    ex:subst("and", "nounand", ex),
+    ex:subst("or", "nounor", ex),
+    ex:subst("not", "nounnot", ex),
+    ex:if not ev(numberp(ex), simp) then logic_simplify(ex) else ex,    
     ex:subst("%and", "and", ex),
     ex:subst("%or", "or", ex),
+    /* %not is not an infix operator... */
+    ex:subst(%not, "not", ex),
     ex:de_morgan(ex),
     ex:trigsimp(ex),
     ex:exponentialize(ex),

diff --git a/stack/maxima/stackmaxima.mac b/stack/maxima/stackmaxima.mac
@@ -134,6 +134,7 @@ load("functs");
 /* Load the logic package, but remove the "eq" infix operator which conflicts with too many existing things. */
 /* We've edited the logic package which over writes the eq operator as xnor.                                 */
 load("stack_logic.lisp");
+load("Ksimplifier.lisp");
 
 /* We don't want to allow people to put boxes round things. */
 box(ex) := ex;

diff --git a/tests/fixtures/answertestfixtures.class.php b/tests/fixtures/answertestfixtures.class.php
@@ -711,6 +711,7 @@ class stack_answertest_test_data {
         ['AlgEquiv', '', 'not(A) and B', 'A implies B', 0, '', ''],
         ['AlgEquiv', '', '(not A and B) or (not B and A)', 'A xor B', 1, 'ATLogic_True.', ''],
         ['AlgEquiv', '', '(A and B) or (not A and not B)', 'A xnor B', 1, 'ATLogic_True.', ''],
+        ['AlgEquiv', '', '((not A) and (not B)) or ((not A) and B)', 'not A', 1, 'ATLogic_True.', ''],
         // We can't apply this simplification to sets, as it breaks sets of inequalities.
         ['AlgEquiv', '', '{not(A) or B,A and B}', '{A implies B,A and B}', 0, 'ATSet_wrongentries.', ''],
         ['AlgEquiv', '', '{A implies B,A and B}', '{not(A) and B,A and B}', 0, 'ATSet_wrongentries.', ''],