Metamath Proof Explorer


Theorem repswsymb

Description: The symbols of a "repeated symbol word". (Contributed by AV, 4-Nov-2018)

Ref Expression
Assertion repswsymb ⊢ S ∈ V ∧ N ∈ ℕ 0 ∧ I ∈ 0 ..^ N → S repeatS N ⁡ I = S

Proof

Step Hyp Ref Expression
1 reps ⊢ S ∈ V ∧ N ∈ ℕ 0 → S repeatS N = x ∈ 0 ..^ N ⟼ S
2 1 3adant3 ⊢ S ∈ V ∧ N ∈ ℕ 0 ∧ I ∈ 0 ..^ N → S repeatS N = x ∈ 0 ..^ N ⟼ S
3 eqidd ⊢ S ∈ V ∧ N ∈ ℕ 0 ∧ I ∈ 0 ..^ N ∧ x = I → S = S
4 simp3 ⊢ S ∈ V ∧ N ∈ ℕ 0 ∧ I ∈ 0 ..^ N → I ∈ 0 ..^ N
5 simp1 ⊢ S ∈ V ∧ N ∈ ℕ 0 ∧ I ∈ 0 ..^ N → S ∈ V
6 2 3 4 5 fvmptd ⊢ S ∈ V ∧ N ∈ ℕ 0 ∧ I ∈ 0 ..^ N → S repeatS N ⁡ I = S