Calculates the dot product of two two-site gates.
a | first operator to be applied |
b | second operator to be applied, dual-space conjugated |
References syten::IPEPS::ATwoOp::left, syten::IPEPS::ATwoOp::op, syten::IPEPS::ATwoOp::right, SYTEN_ASSERT_MSG, and syten::YesNo< struct _prod_conj >::y().