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 0 r r n
3 nn0ex 0 V
4 3 a1i φ 0 V
5 1nn0 1 0
6 5 a1i φ 1 0
7 2 1 4 6 fvmptiunrelexplb1d φ R t* R