let R1, R2 be Ring; :: thesis: ( H3(R1,R2) is Abelian & H3(R1,R2) is add-associative & H3(R1,R2) is right_zeroed & H3(R1,R2) is right_complementable )
set G = BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #);
A1: BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #) is right_complementable
proof
let x be Element of BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #); :: according to ALGSTR_0:def 16 :: thesis: x is right_complementable
take x ; :: according to ALGSTR_0:def 11 :: thesis: x + x = 0. BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #)
thus x + x = 0. BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #) by CARD_1:87, TARSKI:def 1; :: thesis: verum
end;
now
let x, y, z be Element of BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #); :: thesis: ( x + y = y + x & (x + y) + z = x + (y + z) & x + (0. BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #)) = x & ex x' being Element of BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #) st x + x' = 0. BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #) )
( x + y = {} & y + x = {} & (x + y) + z = {} & x + (y + z) = {} & x + (0. BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #)) = {} & x = {} & x + (- x) = {} & 0. BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #) = {} ) by CARD_1:87, TARSKI:def 1;
hence ( x + y = y + x & (x + y) + z = x + (y + z) & x + (0. BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #)) = x & ex x' being Element of BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #) st x + x' = 0. BiModStr(# 1,op2 ,op0 ,(pr2 the carrier of R1,1),(pr1 1,the carrier of R2) #) ) ; :: thesis: verum
end;
hence ( H3(R1,R2) is Abelian & H3(R1,R2) is add-associative & H3(R1,R2) is right_zeroed & H3(R1,R2) is right_complementable ) by A1, RLVECT_1:def 5, RLVECT_1:def 6, RLVECT_1:def 7; :: thesis: verum