| 1 | initial version |
Here is a way:
sage: R.<x,y>=QQbar[]
sage: R({(1,1):2})
2*x*y
sage: R({(1,1):2,(3,4):77})
77*x^3*y^4 + 2*x*y
Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.