Metamath Proof Explorer


Theorem mrcssd

Description: Moore closure preserves subset ordering. Deduction form of mrcss . (Contributed by David Moews, 1-May-2017)

Ref Expression
Hypotheses mrcssd.1 φ A Moore X
mrcssd.2 N = mrCls A
mrcssd.3 φ U V
mrcssd.4 φ V X
Assertion mrcssd φ N U N V

Proof

Step Hyp Ref Expression
1 mrcssd.1 φ A Moore X
2 mrcssd.2 N = mrCls A
3 mrcssd.3 φ U V
4 mrcssd.4 φ V X
5 2 mrcss A Moore X U V V X N U N V
6 1 3 4 5 syl3anc φ N U N V