Metamath Proof Explorer


Theorem fvtrcllb1d

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

Ref Expression
Hypothesis fvtrcllb1d.r ⊢ φ → R ∈ V
Assertion fvtrcllb1d ⊢ φ → R ⊆ t+ ⁡ R

Proof

Step Hyp Ref Expression
1 fvtrcllb1d.r ⊢ φ → R ∈ V
2 dftrcl3 ⊢ t+ = r ∈ V ⟼ ⋃ n ∈ ℕ r ↑ r n
3 nnex ⊢ ℕ ∈ V
4 3 a1i ⊢ φ → ℕ ∈ V
5 1nn ⊢ 1 ∈ ℕ
6 5 a1i ⊢ φ → 1 ∈ ℕ
7 2 1 4 6 fvmptiunrelexplb1d ⊢ φ → R ⊆ t+ ⁡ R