Metamath Proof Explorer


Theorem ttrcleq

Description: Equality theorem for transitive closure. (Contributed by Scott Fenton, 17-Oct-2024)

Ref Expression
Assertion ttrcleq R = S t++ R = t++ S

Proof

Step Hyp Ref Expression
1 breq R = S f m R f suc m f m S f suc m
2 1 ralbidv R = S m n f m R f suc m m n f m S f suc m
3 2 3anbi3d R = S f Fn suc n f = x f n = y m n f m R f suc m f Fn suc n f = x f n = y m n f m S f suc m
4 3 exbidv R = S f f Fn suc n f = x f n = y m n f m R f suc m f f Fn suc n f = x f n = y m n f m S f suc m
5 4 rexbidv R = S n ω 1 𝑜 f f Fn suc n f = x f n = y m n f m R f suc m n ω 1 𝑜 f f Fn suc n f = x f n = y m n f m S f suc m
6 5 opabbidv R = S x y | n ω 1 𝑜 f f Fn suc n f = x f n = y m n f m R f suc m = x y | n ω 1 𝑜 f f Fn suc n f = x f n = y m n f m S f suc m
7 df-ttrcl t++ R = x y | n ω 1 𝑜 f f Fn suc n f = x f n = y m n f m R f suc m
8 df-ttrcl t++ S = x y | n ω 1 𝑜 f f Fn suc n f = x f n = y m n f m S f suc m
9 6 7 8 3eqtr4g R = S t++ R = t++ S