Update src/sage/topology/simplicial_set_examples.py

Co-authored-by: John H. Palmieri <[email protected]>

Author: miguelmarco

src/sage/topology/simplicial_set_examples.py

@@ -801,7 +801,7 @@ def PresentationComplex(G):
     Return a simplicial set constructed from a group presentation.
     The result is a subdivision of the presentation complex.
 
-    The presentation complex has one vertex and one edge for
+    The presentation complex has a single vertex and it has one edge for
     each generator. Then triangles (and eventually new edges
     to glue them) are added to realize the relations.