let L be non empty right_complementable Abelian add-associative right_zeroed distributive unital doubleLoopStr ; for p, q being Polynomial of L
for x being Element of L holds eval ((p - q),x) = (eval (p,x)) - (eval (q,x))
let p, q be Polynomial of L; for x being Element of L holds eval ((p - q),x) = (eval (p,x)) - (eval (q,x))
let x be Element of L; eval ((p - q),x) = (eval (p,x)) - (eval (q,x))
thus eval ((p - q),x) =
(eval (p,x)) + (eval ((- q),x))
by Th19
.=
(eval (p,x)) + (- (eval (q,x)))
by Th20
.=
(eval (p,x)) - (eval (q,x))
by RLVECT_1:def 11
; verum