Theorem tr0 4235

Description: The empty set is transitive. (Contributed by NM, 16-Sep-1993.)

Assertion

Ref	Expression
tr0	|- Tr (/)

Proof of Theorem tr0

Step	Hyp	Ref	Expression
1		0ss 3561	. 2 |- (/) C_ ~P (/)
2		dftr4 4229	. 2 |- ( Tr (/) <-> (/) C_ ~P (/) )
3	1, 2	mpbir 146	1 |- Tr (/)

Syntax hints:   C_ wss 3220   (/)c0 3520   ~Pcpw 3685   Tr wtr 4224

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 623  ax-in2 624  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-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ral 2533  df-v 2823  df-dif 3222  df-in 3226  df-ss 3233  df-nul 3521  df-pw 3687  df-uni 3931  df-tr 4225

This theorem is referenced by:  ord0  4531  ordom  4749