let x be object ; for n being Nat
for c being Complex holds ((0* n) +* (x,c)) ^2 = (0* n) +* (x,(c ^2))
let n be Nat; for c being Complex holds ((0* n) +* (x,c)) ^2 = (0* n) +* (x,(c ^2))
let c be Complex; ((0* n) +* (x,c)) ^2 = (0* n) +* (x,(c ^2))
set f = (0* n) +* (x,c);
set g = (0* n) +* (x,(c ^2));
A1:
dom ((0* n) +* (x,c)) = dom (0* n)
by FUNCT_7:30;
A2:
dom ((0* n) +* (x,(c ^2))) = dom (0* n)
by FUNCT_7:30;
A3:
dom (((0* n) +* (x,c)) ^2) = dom ((0* n) +* (x,c))
by VALUED_1:11;
thus
dom (((0* n) +* (x,c)) ^2) = dom ((0* n) +* (x,(c ^2)))
by A1, A2, VALUED_1:11; FUNCT_1:def 11 for b1 being object holds
( not b1 in dom (((0* n) +* (x,c)) ^2) or (((0* n) +* (x,c)) ^2) . b1 = ((0* n) +* (x,(c ^2))) . b1 )
let a be object ; ( not a in dom (((0* n) +* (x,c)) ^2) or (((0* n) +* (x,c)) ^2) . a = ((0* n) +* (x,(c ^2))) . a )
assume A4:
a in dom (((0* n) +* (x,c)) ^2)
; (((0* n) +* (x,c)) ^2) . a = ((0* n) +* (x,(c ^2))) . a
A5:
(((0* n) +* (x,c)) ^2) . a = (((0* n) +* (x,c)) . a) ^2
by VALUED_1:11;
per cases
( a = x or a <> x )
;
suppose A6:
a = x
;
(((0* n) +* (x,c)) ^2) . a = ((0* n) +* (x,(c ^2))) . athen
((0* n) +* (x,c)) . a = c
by A1, A3, A4, FUNCT_7:31;
hence
(((0* n) +* (x,c)) ^2) . a = ((0* n) +* (x,(c ^2))) . a
by A6, A1, A3, A4, A5, FUNCT_7:31;
verum end; end;