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
|
addid2i |
|
8 |
5 7
|
eqtr2i |
|