let x be set ; for n being Nat
for c being complex number holds ((0* n) +* x,c) ^2 = (0* n) +* x,(c ^2 )
let n be Nat; for c being complex number holds ((0* n) +* x,c) ^2 = (0* n) +* x,(c ^2 )
let c be complex number ; ((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_7:32;
A2:
dom ((0* n) +* x,(c ^2 )) = dom (0* n)
by FUNCT_7:32;
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 17 for b1 being set holds
( not b1 in proj1 (((0* n) +* x,c) ^2 ) or (((0* n) +* x,c) ^2 ) . b1 = ((0* n) +* x,(c ^2 )) . b1 )
let a be set ; ( not a in proj1 (((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_7:33;
hence
(((0* n) +* x,c) ^2 ) . a = ((0* n) +* x,(c ^2 )) . a
by A6, A1, A3, A4, A5, FUNCT_7:33;
verum end; end;