Metamath Proof Explorer


Theorem num0h

Description: Add a zero in the higher places. (Contributed by Mario Carneiro, 18-Feb-2014)

Ref Expression
Hypotheses numnncl.1 T0
numnncl.2 A0
Assertion num0h A=T0+A

Proof

Step Hyp Ref Expression
1 numnncl.1 T0
2 numnncl.2 A0
3 1 nn0cni T
4 3 mul01i T0=0
5 4 oveq1i T0+A=0+A
6 2 nn0cni A
7 6 addlidi 0+A=A
8 5 7 eqtr2i A=T0+A