Description: Lemma for wlkvtxeledg : Two adjacent (not necessarily different) vertices A and B in a walk are incident with an edge E . (Contributed by AV, 4-Apr-2021) (Revised by AV, 5-Nov-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | ifpsnprss |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ssidd | ||
2 | preq2 | ||
3 | dfsn2 | ||
4 | 2 3 | eqtr4di | |
5 | 4 | eqcoms | |
6 | 5 | adantr | |
7 | simpr | ||
8 | 1 6 7 | 3sstr4d | |
9 | 8 | 1fpid3 |