Representants of cosets about furiousgenius

[aidevnn]

FuriousGenius/src/QuotientGroup.jl

Lines 98 to 107 in 3b3a684

	function Op(g::QuotientGroup, e1::Elt, e2::Elt)::Elt
	e0 = Op(g.superGroup, e1, e2)
	r = g.representants[e0]
	# if r != e0
	# println("FIXME ", e1, " * ", e2, " = ", e0, " != ", r, " in ", BaseGroup(e0)) # FIXME
	# # coset representant is actually the minimum for lexical order but
	# # nothing is done to check the set of these representants
	# end
	return r
	end

The commented lines inside this function are printing when a mapping is done and it can be used to find issues when internal direct product is computing.

[aidevnn]

The internal direct product must only be between correct subgroup.
The quotient group of the supergroup with this normal subgroup is a different type of subgroup which element are classes and it is invalid to reuse it for direct product and it must throw an exception. An external direct product is the correct approach.