Metamath Proof Explorer


Theorem 0uhgrsubgr

Description: The null graph (as hypergraph) is a subgraph of all graphs. (Contributed by AV, 17-Nov-2020) (Proof shortened by AV, 28-Nov-2020)

Ref Expression
Assertion 0uhgrsubgr G W S UHGraph Vtx S = S SubGraph G

Proof

Step Hyp Ref Expression
1 3simpa G W S UHGraph Vtx S = G W S UHGraph
2 0ss Vtx G
3 sseq1 Vtx S = Vtx S Vtx G Vtx G
4 2 3 mpbiri Vtx S = Vtx S Vtx G
5 4 3ad2ant3 G W S UHGraph Vtx S = Vtx S Vtx G
6 eqid iEdg S = iEdg S
7 6 uhgrfun S UHGraph Fun iEdg S
8 7 3ad2ant2 G W S UHGraph Vtx S = Fun iEdg S
9 edgval Edg S = ran iEdg S
10 uhgr0vb S UHGraph Vtx S = S UHGraph iEdg S =
11 rneq iEdg S = ran iEdg S = ran
12 rn0 ran =
13 11 12 eqtrdi iEdg S = ran iEdg S =
14 10 13 syl6bi S UHGraph Vtx S = S UHGraph ran iEdg S =
15 14 ex S UHGraph Vtx S = S UHGraph ran iEdg S =
16 15 pm2.43a S UHGraph Vtx S = ran iEdg S =
17 16 a1i G W S UHGraph Vtx S = ran iEdg S =
18 17 3imp G W S UHGraph Vtx S = ran iEdg S =
19 9 18 syl5eq G W S UHGraph Vtx S = Edg S =
20 egrsubgr G W S UHGraph Vtx S Vtx G Fun iEdg S Edg S = S SubGraph G
21 1 5 8 19 20 syl112anc G W S UHGraph Vtx S = S SubGraph G