Theorem 2ordpr 4573

Description: Version of 2on 6513 with the definition of 2o expanded and expressed in terms of Ord. (Contributed by Jim Kingdon, 29-Aug-2021.)

Assertion

Ref	Expression
2ordpr	|- Ord { (/) , { (/) } }

Proof of Theorem 2ordpr

Step	Hyp	Ref	Expression
1		ord0 4439	. . 3 |- Ord (/)
2		ordsucim 4549	. . 3 |- ( Ord (/) -> Ord suc (/) )
3		ordsucim 4549	. . 3 |- ( Ord suc (/) -> Ord suc suc (/) )
4	1, 2, 3	mp2b 8	. 2 |- Ord suc suc (/)
5		df-suc 4419	. . . 4 |- suc { (/) } = ( { (/) } u. { { (/) } } )
6		suc0 4459	. . . . 5 |- suc (/) = { (/) }
7		suceq 4450	. . . . 5 |- ( suc (/) = { (/) } -> suc suc (/) = suc { (/) } )
8	6, 7	ax-mp 5	. . . 4 |- suc suc (/) = suc { (/) }
9		df-pr 3640	. . . 4 |- { (/) , { (/) } } = ( { (/) } u. { { (/) } } )
10	5, 8, 9	3eqtr4i 2236	. . 3 |- suc suc (/) = { (/) , { (/) } }
11		ordeq 4420	. . 3 |- ( suc suc (/) = { (/) , { (/) } } -> ( Ord suc suc (/) <-> Ord { (/) , { (/) } } ) )
12	10, 11	ax-mp 5	. 2 |- ( Ord suc suc (/) <-> Ord { (/) , { (/) } } )
13	4, 12	mpbi 145	1 |- Ord { (/) , { (/) } }

Syntax hints:   <-> wb 105   = wceq 1373   u. cun 3164   (/)c0 3460   {csn 3633   {cpr 3634   Ord word 4410   suc csuc 4413

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-in1 615  ax-in2 616  ax-io 711  ax-5 1470  ax-7 1471  ax-gen 1472  ax-ie1 1516  ax-ie2 1517  ax-8 1527  ax-10 1528  ax-11 1529  ax-i12 1530  ax-bndl 1532  ax-4 1533  ax-17 1549  ax-i9 1553  ax-ial 1557  ax-i5r 1558  ax-ext 2187

This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1484  df-sb 1786  df-clab 2192  df-cleq 2198  df-clel 2201  df-nfc 2337  df-ral 2489  df-rex 2490  df-v 2774  df-dif 3168  df-un 3170  df-in 3172  df-ss 3179  df-nul 3461  df-pw 3618  df-sn 3639  df-pr 3640  df-uni 3851  df-tr 4144  df-iord 4414  df-suc 4419

This theorem is referenced by:  ontr2exmid  4574  ordtri2or2exmidlem  4575  onsucelsucexmidlem  4578