Metamath Proof Explorer


Theorem ntrclsfv2

Description: If (pseudo-)interior and (pseudo-)closure functions are related by the duality operator then there is a functional relation between them (Contributed by RP, 28-May-2021)

Ref Expression
Hypotheses ntrcls.o O = i V k 𝒫 i 𝒫 i j 𝒫 i i k i j
ntrcls.d D = O B
ntrcls.r φ I D K
Assertion ntrclsfv2 φ D K = I

Proof

Step Hyp Ref Expression
1 ntrcls.o O = i V k 𝒫 i 𝒫 i j 𝒫 i i k i j
2 ntrcls.d D = O B
3 ntrcls.r φ I D K
4 1 2 3 ntrclsnvobr φ K D I
5 1 2 4 ntrclsfv1 φ D K = I