fix typo

src/pystencils/backend/kernelcreation/typification.py

@@ -96,7 +96,7 @@ class TypeContext:
         Otherwise, the expression is deferred, and a type will be applied to it as soon as `apply_type` is
         called on this context.
 
-        It the expression already has a data type set, it must be equal to the inferred type.
+        If the expression already has a data type set, it must be equal to the inferred type.
         """
 
         if self._target_type is None: