Theorem inteq 3891

Description: Equality law for intersection. (Contributed by NM, 13-Sep-1999.)

Assertion

Ref	Expression
inteq	⊢ (𝐴 = 𝐵 → ∩ 𝐴 = ∩ 𝐵)

Proof of Theorem inteq

Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		raleq 2703	. . 3 ⊢ (𝐴 = 𝐵 → (∀𝑦 ∈ 𝐴 𝑥 ∈ 𝑦 ↔ ∀𝑦 ∈ 𝐵 𝑥 ∈ 𝑦))
2	1	abbidv 2324	. 2 ⊢ (𝐴 = 𝐵 → {𝑥 ∣ ∀𝑦 ∈ 𝐴 𝑥 ∈ 𝑦} = {𝑥 ∣ ∀𝑦 ∈ 𝐵 𝑥 ∈ 𝑦})
3		dfint2 3890	. 2 ⊢ ∩ 𝐴 = {𝑥 ∣ ∀𝑦 ∈ 𝐴 𝑥 ∈ 𝑦}
4		dfint2 3890	. 2 ⊢ ∩ 𝐵 = {𝑥 ∣ ∀𝑦 ∈ 𝐵 𝑥 ∈ 𝑦}
5	2, 3, 4	3eqtr4g 2264	1 ⊢ (𝐴 = 𝐵 → ∩ 𝐴 = ∩ 𝐵)

Syntax hints:   → wi 4   = wceq 1373  {cab 2192  ∀wral 2485  ∩ cint 3888

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2188

This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1485  df-sb 1787  df-clab 2193  df-cleq 2199  df-clel 2202  df-nfc 2338  df-ral 2490  df-int 3889

This theorem is referenced by:  inteqi  3892  inteqd  3893  uniintsnr  3924  rint0  3927  intexr  4199  onintexmid  4626  elreldm  4910  elxp5  5177  1stval2  6251  fundmen  6909  xpsnen  6928  fiintim  7040  elfir  7087  fiinopn  14526  bj-intexr  15958