Description: A standard nonnegative integer is an extended nonnegative integer. (Contributed by AV, 10-Dec-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | nn0xnn0 | |- ( A e. NN0 -> A e. NN0* ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nn0ssxnn0 | |- NN0 C_ NN0* |
|
2 | 1 | sseli | |- ( A e. NN0 -> A e. NN0* ) |