FlattenMapper: mod 1 is zero

Author: inducer

pymbolic/mapper/flattener.py

@@ -88,7 +88,8 @@ def map_remainder(self, expr: p.Remainder) -> ExpressionT:
         if p.is_zero(r_num):
             return 0
         if p.is_zero(r_den - 1):
-            return r_num
+            # mod 1 is zero
+            return 0
 
         return expr.__class__(r_num, r_den)