Metamath Proof Explorer


Theorem xmullem

Description: Lemma for rexmul . (Contributed by Mario Carneiro, 20-Aug-2015)

Ref Expression
Assertion xmullem ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∨ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∨ B < 0 ∧ A = −∞ ∨ 0 < A ∧ B = +∞ ∨ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∨ B < 0 ∧ A = +∞ ∨ 0 < A ∧ B = −∞ ∨ A < 0 ∧ B = +∞ → A ∈ ℝ

Proof

Step Hyp Ref Expression
1 ioran ⊢ ¬ A = 0 ∨ B = 0 ↔ ¬ A = 0 ∧ ¬ B = 0
2 1 anbi2i ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∨ B = 0 ↔ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0
3 ioran ⊢ ¬ 0 < B ∧ A = +∞ ∨ B < 0 ∧ A = −∞ ∨ 0 < A ∧ B = +∞ ∨ A < 0 ∧ B = −∞ ↔ ¬ 0 < B ∧ A = +∞ ∨ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∨ A < 0 ∧ B = −∞
4 ioran ⊢ ¬ 0 < B ∧ A = +∞ ∨ B < 0 ∧ A = −∞ ↔ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞
5 ioran ⊢ ¬ 0 < A ∧ B = +∞ ∨ A < 0 ∧ B = −∞ ↔ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞
6 4 5 anbi12i ⊢ ¬ 0 < B ∧ A = +∞ ∨ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∨ A < 0 ∧ B = −∞ ↔ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞
7 3 6 bitri ⊢ ¬ 0 < B ∧ A = +∞ ∨ B < 0 ∧ A = −∞ ∨ 0 < A ∧ B = +∞ ∨ A < 0 ∧ B = −∞ ↔ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞
8 ioran ⊢ ¬ 0 < B ∧ A = −∞ ∨ B < 0 ∧ A = +∞ ∨ 0 < A ∧ B = −∞ ∨ A < 0 ∧ B = +∞ ↔ ¬ 0 < B ∧ A = −∞ ∨ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∨ A < 0 ∧ B = +∞
9 ioran ⊢ ¬ 0 < B ∧ A = −∞ ∨ B < 0 ∧ A = +∞ ↔ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞
10 ioran ⊢ ¬ 0 < A ∧ B = −∞ ∨ A < 0 ∧ B = +∞ ↔ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞
11 9 10 anbi12i ⊢ ¬ 0 < B ∧ A = −∞ ∨ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∨ A < 0 ∧ B = +∞ ↔ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞
12 8 11 bitri ⊢ ¬ 0 < B ∧ A = −∞ ∨ B < 0 ∧ A = +∞ ∨ 0 < A ∧ B = −∞ ∨ A < 0 ∧ B = +∞ ↔ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞
13 7 12 anbi12i ⊢ ¬ 0 < B ∧ A = +∞ ∨ B < 0 ∧ A = −∞ ∨ 0 < A ∧ B = +∞ ∨ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∨ B < 0 ∧ A = +∞ ∨ 0 < A ∧ B = −∞ ∨ A < 0 ∧ B = +∞ ↔ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞
14 simplll ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → A ∈ ℝ *
15 elxr ⊢ A ∈ ℝ * ↔ A ∈ ℝ ∨ A = +∞ ∨ A = −∞
16 14 15 sylib ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → A ∈ ℝ ∨ A = +∞ ∨ A = −∞
17 idd ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → A ∈ ℝ → A ∈ ℝ
18 simprlr ⊢ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → ¬ B < 0 ∧ A = +∞
19 18 adantl ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → ¬ B < 0 ∧ A = +∞
20 19 pm2.21d ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → B < 0 ∧ A = +∞ → A ∈ ℝ
21 20 expdimp ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ ∧ B < 0 → A = +∞ → A ∈ ℝ
22 simplrr ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → ¬ B = 0
23 22 pm2.21d ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → B = 0 → A = +∞ → A ∈ ℝ
24 23 imp ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ ∧ B = 0 → A = +∞ → A ∈ ℝ
25 simplll ⊢ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → ¬ 0 < B ∧ A = +∞
26 25 adantl ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → ¬ 0 < B ∧ A = +∞
27 26 pm2.21d ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → 0 < B ∧ A = +∞ → A ∈ ℝ
28 27 expdimp ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ ∧ 0 < B → A = +∞ → A ∈ ℝ
29 simpllr ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → B ∈ ℝ *
30 0xr ⊢ 0 ∈ ℝ *
31 xrltso ⊢ < Or ℝ *
32 solin ⊢ < Or ℝ * ∧ B ∈ ℝ * ∧ 0 ∈ ℝ * → B < 0 ∨ B = 0 ∨ 0 < B
33 31 32 mpan ⊢ B ∈ ℝ * ∧ 0 ∈ ℝ * → B < 0 ∨ B = 0 ∨ 0 < B
34 29 30 33 sylancl ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → B < 0 ∨ B = 0 ∨ 0 < B
35 21 24 28 34 mpjao3dan ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → A = +∞ → A ∈ ℝ
36 simpllr ⊢ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → ¬ B < 0 ∧ A = −∞
37 36 adantl ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → ¬ B < 0 ∧ A = −∞
38 37 pm2.21d ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → B < 0 ∧ A = −∞ → A ∈ ℝ
39 38 expdimp ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ ∧ B < 0 → A = −∞ → A ∈ ℝ
40 22 pm2.21d ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → B = 0 → A = −∞ → A ∈ ℝ
41 40 imp ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ ∧ B = 0 → A = −∞ → A ∈ ℝ
42 simprll ⊢ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → ¬ 0 < B ∧ A = −∞
43 42 adantl ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → ¬ 0 < B ∧ A = −∞
44 43 pm2.21d ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → 0 < B ∧ A = −∞ → A ∈ ℝ
45 44 expdimp ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ ∧ 0 < B → A = −∞ → A ∈ ℝ
46 39 41 45 34 mpjao3dan ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → A = −∞ → A ∈ ℝ
47 17 35 46 3jaod ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → A ∈ ℝ ∨ A = +∞ ∨ A = −∞ → A ∈ ℝ
48 16 47 mpd ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∧ ¬ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∧ ¬ B < 0 ∧ A = −∞ ∧ ¬ 0 < A ∧ B = +∞ ∧ ¬ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∧ ¬ B < 0 ∧ A = +∞ ∧ ¬ 0 < A ∧ B = −∞ ∧ ¬ A < 0 ∧ B = +∞ → A ∈ ℝ
49 2 13 48 syl2anb ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∨ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∨ B < 0 ∧ A = −∞ ∨ 0 < A ∧ B = +∞ ∨ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∨ B < 0 ∧ A = +∞ ∨ 0 < A ∧ B = −∞ ∨ A < 0 ∧ B = +∞ → A ∈ ℝ
50 49 anassrs ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ ¬ A = 0 ∨ B = 0 ∧ ¬ 0 < B ∧ A = +∞ ∨ B < 0 ∧ A = −∞ ∨ 0 < A ∧ B = +∞ ∨ A < 0 ∧ B = −∞ ∧ ¬ 0 < B ∧ A = −∞ ∨ B < 0 ∧ A = +∞ ∨ 0 < A ∧ B = −∞ ∨ A < 0 ∧ B = +∞ → A ∈ ℝ