Proof of Theorem difrab
| Step | Hyp | Ref
 | Expression | 
| 1 |   | df-rab 2484 | 
. . 3
⊢ {𝑥 ∈ 𝐴 ∣ 𝜑} = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} | 
| 2 |   | df-rab 2484 | 
. . 3
⊢ {𝑥 ∈ 𝐴 ∣ 𝜓} = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜓)} | 
| 3 | 1, 2 | difeq12i 3279 | 
. 2
⊢ ({𝑥 ∈ 𝐴 ∣ 𝜑} ∖ {𝑥 ∈ 𝐴 ∣ 𝜓}) = ({𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} ∖ {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜓)}) | 
| 4 |   | df-rab 2484 | 
. . 3
⊢ {𝑥 ∈ 𝐴 ∣ (𝜑 ∧ ¬ 𝜓)} = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ (𝜑 ∧ ¬ 𝜓))} | 
| 5 |   | difab 3432 | 
. . . 4
⊢ ({𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} ∖ {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜓)}) = {𝑥 ∣ ((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ (𝑥 ∈ 𝐴 ∧ 𝜓))} | 
| 6 |   | anass 401 | 
. . . . . 6
⊢ (((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ 𝜓) ↔ (𝑥 ∈ 𝐴 ∧ (𝜑 ∧ ¬ 𝜓))) | 
| 7 |   | simpr 110 | 
. . . . . . . . 9
⊢ ((𝑥 ∈ 𝐴 ∧ 𝜓) → 𝜓) | 
| 8 | 7 | con3i 633 | 
. . . . . . . 8
⊢ (¬
𝜓 → ¬ (𝑥 ∈ 𝐴 ∧ 𝜓)) | 
| 9 | 8 | anim2i 342 | 
. . . . . . 7
⊢ (((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ 𝜓) → ((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ (𝑥 ∈ 𝐴 ∧ 𝜓))) | 
| 10 |   | pm3.2 139 | 
. . . . . . . . . 10
⊢ (𝑥 ∈ 𝐴 → (𝜓 → (𝑥 ∈ 𝐴 ∧ 𝜓))) | 
| 11 | 10 | adantr 276 | 
. . . . . . . . 9
⊢ ((𝑥 ∈ 𝐴 ∧ 𝜑) → (𝜓 → (𝑥 ∈ 𝐴 ∧ 𝜓))) | 
| 12 | 11 | con3d 632 | 
. . . . . . . 8
⊢ ((𝑥 ∈ 𝐴 ∧ 𝜑) → (¬ (𝑥 ∈ 𝐴 ∧ 𝜓) → ¬ 𝜓)) | 
| 13 | 12 | imdistani 445 | 
. . . . . . 7
⊢ (((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ (𝑥 ∈ 𝐴 ∧ 𝜓)) → ((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ 𝜓)) | 
| 14 | 9, 13 | impbii 126 | 
. . . . . 6
⊢ (((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ 𝜓) ↔ ((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ (𝑥 ∈ 𝐴 ∧ 𝜓))) | 
| 15 | 6, 14 | bitr3i 186 | 
. . . . 5
⊢ ((𝑥 ∈ 𝐴 ∧ (𝜑 ∧ ¬ 𝜓)) ↔ ((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ (𝑥 ∈ 𝐴 ∧ 𝜓))) | 
| 16 | 15 | abbii 2312 | 
. . . 4
⊢ {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ (𝜑 ∧ ¬ 𝜓))} = {𝑥 ∣ ((𝑥 ∈ 𝐴 ∧ 𝜑) ∧ ¬ (𝑥 ∈ 𝐴 ∧ 𝜓))} | 
| 17 | 5, 16 | eqtr4i 2220 | 
. . 3
⊢ ({𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} ∖ {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜓)}) = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ (𝜑 ∧ ¬ 𝜓))} | 
| 18 | 4, 17 | eqtr4i 2220 | 
. 2
⊢ {𝑥 ∈ 𝐴 ∣ (𝜑 ∧ ¬ 𝜓)} = ({𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} ∖ {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜓)}) | 
| 19 | 3, 18 | eqtr4i 2220 | 
1
⊢ ({𝑥 ∈ 𝐴 ∣ 𝜑} ∖ {𝑥 ∈ 𝐴 ∣ 𝜓}) = {𝑥 ∈ 𝐴 ∣ (𝜑 ∧ ¬ 𝜓)} |