scheme :: GROUP_10:sch 1
ExLeftOperation{ F₁() -> set , F₂() -> non empty Group-like multMagma , F₃( Element of F₂()) -> Function of F₁(),F₁() } :

ex T being LeftOperation of F₂(),F₁() st
for s being Element of F₂() holds T . s = F₃(s)

provided

A1: F₃((1_ F₂())) = id F₁() and
A2: for s1, s2 being Element of F₂() holds F₃((s1 * s2)) = F₃(s1) * F₃(s2)