From 1984990714aa9e34c22eca94609ef84c6162c12d Mon Sep 17 00:00:00 2001
From: "K. Andrew Parker" <kparker@citytech.cuny.edu>
Date: Wed, 26 Jul 2023 16:20:24 -0400
Subject: [PATCH] parse derivatives instead of just relying on tree

---
 lib/Parser/Differentiation.pm | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/Parser/Differentiation.pm b/lib/Parser/Differentiation.pm
index b4cb96a178..5e8eacecf3 100644
--- a/lib/Parser/Differentiation.pm
+++ b/lib/Parser/Differentiation.pm
@@ -39,7 +39,11 @@ sub Parser::D {
 		return (0 * $self)->reduce('0*x' => 1) unless defined $self->{variables}{$x};
 		$f = $f->D($x);
 	}
-	return $self->new($f);
+	my $deriv = $self->new($f);
+	$deriv->{string} = $deriv->{tree}->string;
+	$deriv->tokenize;
+	$deriv->parse;
+	return $deriv;
 }
 
 #