From: Michael Orlitzky <michael@orlitzky.com>
Date: Tue, 23 Feb 2021 14:02:43 +0000 (-0500)
Subject: eja: fix element constructor error message for Cartesian products.
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=1cdc6f6bf992dc522ff144b1e624c9e92c95c0b9;p=sage.d.git

eja: fix element constructor error message for Cartesian products.
---

diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py
index 0653396..7fb8027 100644
--- a/mjo/eja/eja_algebra.py
+++ b/mjo/eja/eja_algebra.py
@@ -3157,8 +3157,11 @@ class CartesianProductEJA(CombinatorialFreeModule_CartesianProduct,
             e(0, 1) + e(1, 2)
         """
         m = len(self.cartesian_factors())
-        z = tuple( self.cartesian_factors()[i](elt[i]) for i in range(m) )
-        return self._cartesian_product_of_elements(z)
+        try:
+            z = tuple( self.cartesian_factors()[i](elt[i]) for i in range(m) )
+            return self._cartesian_product_of_elements(z)
+        except:
+            raise ValueError("not an element of this algebra")
 
     Element = FiniteDimensionalEJAElement