| 1 | initial version |
I am not sure you can hope for more relations than working in an abstract free group if you do not assume anything about your unitary matrices:
sage: G.<U1,U2,U3> = FreeGroup()
sage: G
Free Group on generators {U1, U2, U3}
sage: A = U1*U1^(-1)*U2
sage: A
U2
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.