Metamath Proof Explorer


Theorem fvrtrcllb1d

Description: A set is a subset of its image under the reflexive-transitive closure. (Contributed by RP, 22-Jul-2020)

Ref Expression
Hypothesis fvrtrcllb1d.r ⊢ φ → R ∈ V
Assertion fvrtrcllb1d ⊢ φ → R ⊆ t* ⁡ R

Proof

Step Hyp Ref Expression
1 fvrtrcllb1d.r ⊢ φ → R ∈ V
2 dfrtrcl3 ⊢ t* = r ∈ V ⟼ ⋃ n ∈ ℕ 0 r ↑ r n
3 nn0ex ⊢ ℕ 0 ∈ V
4 3 a1i ⊢ φ → ℕ 0 ∈ V
5 1nn0 ⊢ 1 ∈ ℕ 0
6 5 a1i ⊢ φ → 1 ∈ ℕ 0
7 2 1 4 6 fvmptiunrelexplb1d ⊢ φ → R ⊆ t* ⁡ R