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 r r n
3 nnex V
4 3 a1i φ V
5 1nn 1
6 5 a1i φ 1
7 2 1 4 6 fvmptiunrelexplb1d φ R t+ R