[WWcvs] pg: Check that "and" and "or" combine inequalities that use the same variable.

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

Log Message:
-----------
Check that "and" and "or" combine inequalities that use the same variable.

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

Revision Data
-------------
Index: contextInequalities.pl
===================================================================
RCS file: /webwork/cvs/system/pg/macros/contextInequalities.pl,v
retrieving revision 1.9
retrieving revision 1.10
diff -Lmacros/contextInequalities.pl -Lmacros/contextInequalities.pl -u -r1.9 -r1.10
--- macros/contextInequalities.pl
+++ macros/contextInequalities.pl
@@ -275,8 +275,10 @@
   my $self = shift;
   $self->Error("The operands of '%s' must be inequalities",$self->{bop})
     unless $self->{lop}{isInequality} && $self->{rop}{isInequality};
+  $self->Error("Inequalities combined by '%s' must both use the same variable",$self->{bop})
+    unless $self->{lop}{varName} eq $self->{rop}{varName};
   $self->{type} = Value::Type("Interval",2);
-  $self->{varName} = $self->{lop}{varName} || $self->{rop}{varName};
+  $self->{varName} = $self->{lop}{varName};
   $self->{isInequality} = 1;
 }
 
@@ -293,8 +295,10 @@
   my $self = shift;
   $self->Error("The operands of '%s' must be inequalities",$self->{bop})
     unless $self->{lop}{isInequality} && $self->{rop}{isInequality};
+  $self->Error("Inequalities combined by '%s' must both use the same variable",$self->{bop})
+    unless $self->{lop}{varName} eq $self->{rop}{varName};
   $self->{type} = Value::Type("Interval",2);
-  $self->{varName} = $self->{lop}{varName} || $self->{rop}{varName};
+  $self->{varName} = $self->{lop}{varName};
   $self->{isInequality} = 1;
 }