let I be non empty set ; :: thesis: for M being ManySortedSet of I holds id M is Equivalence_Relation of M

let M be ManySortedSet of I; :: thesis: id M is Equivalence_Relation of M

set J = id M;

for i being set st i in I holds

(id M) . i is Relation of (M . i)

for i being set

for R being Relation of (M . i) st i in I & J . i = R holds

R is Equivalence_Relation of (M . i)

let M be ManySortedSet of I; :: thesis: id M is Equivalence_Relation of M

set J = id M;

for i being set st i in I holds

(id M) . i is Relation of (M . i)

proof

then reconsider J = id M as ManySortedRelation of M by MSUALG_4:def 1;
let i be set ; :: thesis: ( i in I implies (id M) . i is Relation of (M . i) )

assume i in I ; :: thesis: (id M) . i is Relation of (M . i)

then (id M) . i = id (M . i) by MSUALG_3:def 1;

hence (id M) . i is Relation of (M . i) ; :: thesis: verum

end;assume i in I ; :: thesis: (id M) . i is Relation of (M . i)

then (id M) . i = id (M . i) by MSUALG_3:def 1;

hence (id M) . i is Relation of (M . i) ; :: thesis: verum

for i being set

for R being Relation of (M . i) st i in I & J . i = R holds

R is Equivalence_Relation of (M . i)

proof

hence
id M is Equivalence_Relation of M
by MSUALG_4:def 2; :: thesis: verum
let i be set ; :: thesis: for R being Relation of (M . i) st i in I & J . i = R holds

R is Equivalence_Relation of (M . i)

let R be Relation of (M . i); :: thesis: ( i in I & J . i = R implies R is Equivalence_Relation of (M . i) )

assume that

A1: i in I and

A2: J . i = R ; :: thesis: R is Equivalence_Relation of (M . i)

J . i = id (M . i) by A1, MSUALG_3:def 1;

hence R is Equivalence_Relation of (M . i) by A2, EQREL_1:3; :: thesis: verum

end;R is Equivalence_Relation of (M . i)

let R be Relation of (M . i); :: thesis: ( i in I & J . i = R implies R is Equivalence_Relation of (M . i) )

assume that

A1: i in I and

A2: J . i = R ; :: thesis: R is Equivalence_Relation of (M . i)

J . i = id (M . i) by A1, MSUALG_3:def 1;

hence R is Equivalence_Relation of (M . i) by A2, EQREL_1:3; :: thesis: verum