Theorem prsstp13 3864

Description: A pair is a subset of an unordered triple containing its members. (Contributed by Jim Kingdon, 11-Aug-2018.)

Assertion

Ref	Expression
prsstp13	|- { A , C } C_ { A , B , C }

Proof of Theorem prsstp13

Step	Hyp	Ref	Expression
1		prsstp12 3863	. 2 |- { A , C } C_ { A , C , B }
2		tpcomb 3802	. 2 |- { A , B , C } = { A , C , B }
3	1, 2	sseqtrri 3283	1 |- { A , C } C_ { A , B , C }

Syntax hints:   C_ wss 3220   {cpr 3706   {ctp 3707

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220

This theorem depends on definitions:  df-bi 117  df-3or 1010  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-v 2823  df-un 3224  df-in 3226  df-ss 3233  df-sn 3711  df-pr 3712  df-tp 3713

This theorem is referenced by:  sstpr  3877