let B be non empty set ; :: thesis: for P being BinOp of B
for e being Element of B st B = A \ {nd} & e = nm & P = om1 ! A,nd holds
addLoopStr(# B,P,e #) is AbGroup
let P be BinOp of B; :: thesis: for e being Element of B st B = A \ {nd} & e = nm & P = om1 ! A,nd holds
addLoopStr(# B,P,e #) is AbGroup
let e be Element of B; :: thesis: ( B = A \ {nd} & e = nm & P = om1 ! A,nd implies addLoopStr(# B,P,e #) is AbGroup )
assume A1:
( B = A \ {nd} & e = nm & P = om1 ! A,nd )
; :: thesis: addLoopStr(# B,P,e #) is AbGroup
A2:
for a, b, c being Element of B holds P . (P . a,b),c = P . a,(P . b,c)
proof
let a,
b,
c be
Element of
B;
:: thesis: P . (P . a,b),c = P . a,(P . b,c)
(
a = In 1,2 &
b = In 1,2 &
c = In 1,2 )
by A1, Lm17, TARSKI:def 1;
hence
P . (P . a,b),
c = P . a,
(P . b,c)
by A1, Lm17, TARSKI:def 1;
:: thesis: verum
end;
A3:
for a being Element of addLoopStr(# B,P,e #) holds a + (0. addLoopStr(# B,P,e #)) = a
proof
let a be
Element of
addLoopStr(#
B,
P,
e #);
:: thesis: a + (0. addLoopStr(# B,P,e #)) = a
a = In 1,2
by A1, Lm17, TARSKI:def 1;
hence
a + (0. addLoopStr(# B,P,e #)) = a
by A1, Lm17, TARSKI:def 1;
:: thesis: verum
end;
A4:
addLoopStr(# B,P,e #) is right_complementable
A5:
for a, b, c being Element of addLoopStr(# B,P,e #) holds (a + b) + c = a + (b + c)
by A2;
for a, b being Element of addLoopStr(# B,P,e #) holds a + b = b + a
hence
addLoopStr(# B,P,e #) is AbGroup
by A3, A4, A5, RLVECT_1:def 5, RLVECT_1:def 6, RLVECT_1:def 7; :: thesis: verum