From 2aaf7c929b42153422def7046a9b7fcc7afe3581 Mon Sep 17 00:00:00 2001 From: sangwinc Date: Fri, 8 May 2026 09:55:28 +0100 Subject: [PATCH] Fix ATDiff simplification problem: issue #1749. --- stack/maxima/stackmaxima.mac | 2 +- tests/fixtures/answertestfixtures.class.php | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/stack/maxima/stackmaxima.mac b/stack/maxima/stackmaxima.mac index c829d59aafe..4c798ff1384 100644 --- a/stack/maxima/stackmaxima.mac +++ b/stack/maxima/stackmaxima.mac @@ -3385,7 +3385,7 @@ ATDiff(sa, sb, so) := Difffun(SA, SB, v) := block([val, rawmk, ansnote, fb, ret, lSAv, lSBv, mSAv, mSBv], val:true, rawmk:false, fb:"", ansnote:"", ret:[val, rawmk, ansnote, fb], - if algebraic_equivalence(SA, SB) then + if ev(algebraic_equivalence(SA, SB), simp) then (rawmk:true, ansnote:StackAddNote("", "ATDiff_true")) else if ev(algebraic_equivalence(diff(SA,v), int(SB,v)), simp) then ( diff --git a/tests/fixtures/answertestfixtures.class.php b/tests/fixtures/answertestfixtures.class.php index 115bc321803..2ad427be8e0 100644 --- a/tests/fixtures/answertestfixtures.class.php +++ b/tests/fixtures/answertestfixtures.class.php @@ -1868,6 +1868,7 @@ class stack_answertest_test_data { ['Diff', 'x', '3*x/root(3*x^2+2)', '3*x/sqrt(3*x^2+2)', 1, 'ATDiff_true.', ''], ['Diff', 'x', '3*x/\'root(3*x^2+2)', '3*x/sqrt(3*x^2+2)', 1, 'ATDiff_true.', ''], ['Diff', 'x', '\'root(2*x/10+1)', 'sqrt((2*x+10)/10)', 1, 'ATDiff_true.', ''], + ['Diff', 'x', 'e^(sqrt(x-2))/(2*sqrt(x-2))', 'e^(sqrt(x)-2)/(2*sqrt(x))', 0, '', ''], ['Int', '', '1/0', '1', -1, 'STACKERROR_OPTION.', ''], ['Int', 'x', '1/0', '1', -1, 'ATInt_STACKERROR_SAns.', ''],