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 ( 𝜑𝑅 ∈ V )
Assertion fvtrcllb1d ( 𝜑𝑅 ⊆ ( t+ ‘ 𝑅 ) )

Proof

Step Hyp Ref Expression
1 fvtrcllb1d.r ( 𝜑𝑅 ∈ V )
2 dftrcl3 t+ = ( 𝑟 ∈ V ↦ 𝑛 ∈ ℕ ( 𝑟𝑟 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 ( 𝜑𝑅 ⊆ ( t+ ‘ 𝑅 ) )