Theorem df1o2 4140

Description: Expanded value of the ordinal number 1.

Assertion

Ref	Expression
df1o2	|- 1o = {(/)}

Proof of Theorem df1o2

Step	Hyp	Ref	Expression
1		df-1o 4133	. 2 |- 1o = suc (/)
2		suc0 3043	. 2 |- suc (/) = {(/)}
3	1, 2	eqtr 1495	1 |- 1o = {(/)}

Syntax hints:   = wceq 956  (/)c0 2280  {csn 2409  suc csuc 2950  1oc1o 4128

This theorem is referenced by:  df2o2 4141  1ne0 4142  el1o 4146  map0e 4342  map0 4344  ensn1 4424  en1 4426  map1 4430  1sdom2 4526  pwfiOLD 4571  xp1en 4927  xp2cda 4928  infmap2 7581

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 962  ax-gen 963  ax-8 964  ax-10 966  ax-12 968  ax-17 971  ax-4 973  ax-5o 975  ax-6o 978  ax-9o 1123  ax-10o 1140  ax-16 1210  ax-11o 1218  ax-ext 1459

This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-ex 981  df-sb 1172  df-clab 1464  df-cleq 1469  df-clel 1472  df-v 1812  df-dif 2049  df-un 2050  df-nul 2281  df-suc 2954  df-1o 4133

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