Trac #25640: converting back Zmod(n) from magma to sage

from ticket #4896 URL: https://trac.sagemath.org/25640 Reported by: chapoton Ticket author(s): Frédéric Chapoton Reviewer(s): Travis Scrimshaw
sagemath · Jun 24, 2018 · 94e5823 · 94e5823
2 parents d837c6d + 895c9b3
commit 94e5823
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diff --git a/src/ext/magma/sage/basic.m b/src/ext/magma/sage/basic.m
@@ -118,6 +118,13 @@ intrinsic Sage(X::FldFinElt) -> MonStgElt, BoolElt
     end if;
 end intrinsic;
 
+/* Finite quotients of ZZ */
+
+intrinsic Sage(X::RngIntRes) -> MonStgElt, BoolElt
+{}
+  return Sprintf("Zmod(%o)", Characteristic(X)), false;
+end intrinsic;
+
 /* Approximate fields */
 
 intrinsic Sage(X::FldRe) -> MonStgElt, BoolElt

diff --git a/src/sage/interfaces/magma.py b/src/sage/interfaces/magma.py
@@ -2071,6 +2071,11 @@ def _sage_(self):
             ...
             NameError: name 'K' is not defined
 
+        Finite quotients of ZZ::
+
+            sage: R = Zmod(137)
+            sage: magma(R).sage()  # optional - magma
+            Ring of integers modulo 137
         """
         z, preparse = self.Sage(nvals=2)
         s = str(z)