Metamath Proof Explorer


Theorem divalglem7

Description: Lemma for divalg . (Contributed by Paul Chapman, 21-Mar-2011)

Ref Expression
Hypotheses divalglem7.1 D
divalglem7.2 D 0
Assertion divalglem7 X 0 D 1 K K 0 ¬ X + K D 0 D 1

Proof

Step Hyp Ref Expression
1 divalglem7.1 D
2 divalglem7.2 D 0
3 oveq1 X = if X 0 D 1 X 0 X + K D = if X 0 D 1 X 0 + K D
4 3 eleq1d X = if X 0 D 1 X 0 X + K D 0 D 1 if X 0 D 1 X 0 + K D 0 D 1
5 4 notbid X = if X 0 D 1 X 0 ¬ X + K D 0 D 1 ¬ if X 0 D 1 X 0 + K D 0 D 1
6 5 imbi2d X = if X 0 D 1 X 0 K 0 ¬ X + K D 0 D 1 K 0 ¬ if X 0 D 1 X 0 + K D 0 D 1
7 neeq1 K = if K K 0 K 0 if K K 0 0
8 oveq1 K = if K K 0 K D = if K K 0 D
9 8 oveq2d K = if K K 0 if X 0 D 1 X 0 + K D = if X 0 D 1 X 0 + if K K 0 D
10 9 eleq1d K = if K K 0 if X 0 D 1 X 0 + K D 0 D 1 if X 0 D 1 X 0 + if K K 0 D 0 D 1
11 10 notbid K = if K K 0 ¬ if X 0 D 1 X 0 + K D 0 D 1 ¬ if X 0 D 1 X 0 + if K K 0 D 0 D 1
12 7 11 imbi12d K = if K K 0 K 0 ¬ if X 0 D 1 X 0 + K D 0 D 1 if K K 0 0 ¬ if X 0 D 1 X 0 + if K K 0 D 0 D 1
13 nnabscl D D 0 D
14 1 2 13 mp2an D
15 0z 0
16 0le0 0 0
17 14 nngt0i 0 < D
18 14 nnzi D
19 elfzm11 0 D 0 0 D 1 0 0 0 0 < D
20 15 18 19 mp2an 0 0 D 1 0 0 0 0 < D
21 15 16 17 20 mpbir3an 0 0 D 1
22 21 elimel if X 0 D 1 X 0 0 D 1
23 15 elimel if K K 0
24 14 22 23 divalglem6 if K K 0 0 ¬ if X 0 D 1 X 0 + if K K 0 D 0 D 1
25 6 12 24 dedth2h X 0 D 1 K K 0 ¬ X + K D 0 D 1