A set with a binary operation (not necessarily associative)
which satisfies unique solvability of equations. That is,
for all a,b there exist unique x, y satisfying
x a = b and a y = b
Using three binary operations, written as (nonassociative)
multiplication, /, and \ (where x = b/a and y = a\b are the
unique solutions to the equations above), the variety of
quasigroups is defined by the identities