get_branching_rule for F4=>B3 and G2=>A1 should return vectors of the correct length
make CartanType idempotent in get_branching_rule
updated timing information and implemented E6->G2xA2 branching rule
implemented E6->G2xA2 branching rule and corrected wrong timing info on long tests
Merge branch 'public/combinat/15361-branching-rules' of trac.sagemath.org:sage into 15361-branching-rules
implemented multiplication of branching rules
revision of branching rules, including composite rules
F4 => G2xA1 branching rule implemented
E6 => G2xA2 branching rule written without x6 and x7
changed E6=>G2xA2 rule not to use redundant components to weight vector
Use compact representation for Cartan type in WeylCharacterRing repr method
corrections and revisions to existing branching rules and tests
further cleanup and corrections
E8->E7,E7->E6 rules gave correct answers but did not map weight lattice into
weight lattice, hence were broke for composition. This is fixed.
projection branching for reducible types
improved __repr__ for class BranchingRule
revisions to __repr__ method of BranchingRule
revised G2=>A2 rule, added describe() method to class BranchingRule
describe method of BranchingRule
revised test for describe method