Metamath Proof Explorer


Definition df-2o

Description: Define the ordinal number 2. (Contributed by NM, 18-Feb-2004)

Ref Expression
Assertion df-2o 2𝑜=suc1𝑜

Detailed syntax breakdown

Step Hyp Ref Expression
0 c2o class2𝑜
1 c1o class1𝑜
2 1 csuc classsuc1𝑜
3 0 2 wceq wff2𝑜=suc1𝑜