[WWcvs] pg: make reduce work with negative numbers

[dpvc v. a. <we...@ma...>]

Log Message:
-----------
make reduce work with negative numbers

Modified Files:
--------------
    pg/macros:
        contextFraction.pl

Revision Data
-------------
Index: contextFraction.pl
===================================================================
RCS file: /webwork/cvs/system/pg/macros/contextFraction.pl,v
retrieving revision 1.4
retrieving revision 1.5
diff -Lmacros/contextFraction.pl -Lmacros/contextFraction.pl -u -r1.4 -r1.5
--- macros/contextFraction.pl
+++ macros/contextFraction.pl
@@ -476,6 +476,15 @@
   $self->SUPER::class;
 }
 
+#
+#  make isNeg properly handle the modified class
+#
+sub isNeg {
+  my $self = shift;
+  return ($self->class =~ /UOP|MINUS/ && $self->{uop} eq 'u-' && !$self->{op}->{isInfinite});
+
+}
+
 ###########################################################################
 
 package context::Fraction::Value;