Metamath Proof Explorer
Description: Add a zero in the higher places. (Contributed by Mario Carneiro, 18-Feb-2014)
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|
Ref |
Expression |
|
Hypotheses |
numnncl.1 |
|
|
|
numnncl.2 |
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|
Assertion |
num0h |
|
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
numnncl.1 |
|
| 2 |
|
numnncl.2 |
|
| 3 |
1
|
nn0cni |
|
| 4 |
3
|
mul01i |
|
| 5 |
4
|
oveq1i |
|
| 6 |
2
|
nn0cni |
|
| 7 |
6
|
addlidi |
|
| 8 |
5 7
|
eqtr2i |
|