let I be set ; :: thesis: for G being Group
for H being Group-Family of I
for x being Function of I,G
for y being Element of (product H) st x = y & ( for i being object st i in I holds
H . i is Subgroup of G ) holds
support x = support (y,H)

let G be Group; :: thesis: for H being Group-Family of I
for x being Function of I,G
for y being Element of (product H) st x = y & ( for i being object st i in I holds
H . i is Subgroup of G ) holds
support x = support (y,H)

let H be Group-Family of I; :: thesis: for x being Function of I,G
for y being Element of (product H) st x = y & ( for i being object st i in I holds
H . i is Subgroup of G ) holds
support x = support (y,H)

let x be Function of I,G; :: thesis: for y being Element of (product H) st x = y & ( for i being object st i in I holds
H . i is Subgroup of G ) holds
support x = support (y,H)

let y be Element of (product H); :: thesis: ( x = y & ( for i being object st i in I holds
H . i is Subgroup of G ) implies support x = support (y,H) )

assume that
A1: x = y and
A2: for i being object st i in I holds
H . i is Subgroup of G ; :: thesis: support x = support (y,H)
A5: for i being object st i in I holds
1_ (H . i) = 1_ G
proof
let i be object ; :: thesis: ( i in I implies 1_ (H . i) = 1_ G )
assume i in I ; :: thesis: 1_ (H . i) = 1_ G
then H . i is Subgroup of G by A2;
hence 1_ (H . i) = 1_ G by GROUP_2:44; :: thesis: verum
end;
for i being object holds
( i in support (y,H) iff i in support x )
proof
let i be object ; :: thesis: ( i in support (y,H) iff i in support x )
A6: ( i in support x iff ( x . i <> 1_ G & i in I ) ) by Def2;
A7: ( i in support (y,H) iff ( y . i <> 1_ (H . i) & i in I ) ) by Def1;
hereby :: thesis: ( i in support x implies i in support (y,H) )
assume i in support (y,H) ; :: thesis: i in support x
then ( y . i <> 1_ (H . i) & i in I ) by Def1;
hence i in support x by A1, A5, A6; :: thesis: verum
end;
assume i in support x ; :: thesis: i in support (y,H)
then ( x . i <> 1_ G & i in I ) by Def2;
hence i in support (y,H) by A1, A5, A7; :: thesis: verum
end;
hence support x = support (y,H) by TARSKI:2; :: thesis: verum