Theorem intirr 5030

Description: Two ways of saying a relation is irreflexive. Definition of irreflexivity in [Schechter] p. 51. (Contributed by NM, 9-Sep-2004.) (Revised by Andrew Salmon, 27-Aug-2011.)

Assertion

Ref	Expression
intirr	⊢ ((R ∩ I ) = ∅ ↔ ∀x ¬ xRx)

Distinct variable group:   x,R

Proof of Theorem intirr

Dummy variable y is distinct from all other variables.

Step	Hyp	Ref	Expression
1		incom 3449	. . . 4 ⊢ (R ∩ I ) = ( I ∩ R)
2	1	eqeq1i 2360	. . 3 ⊢ ((R ∩ I ) = ∅ ↔ ( I ∩ R) = ∅)
3		disj5 3891	. . 3 ⊢ (( I ∩ R) = ∅ ↔ I ⊆ ∼ R)
4		ssrel 4845	. . 3 ⊢ ( I ⊆ ∼ R ↔ ∀x∀y(⟨x, y⟩ ∈ I → ⟨x, y⟩ ∈ ∼ R))
5	2, 3, 4	3bitri 262	. 2 ⊢ ((R ∩ I ) = ∅ ↔ ∀x∀y(⟨x, y⟩ ∈ I → ⟨x, y⟩ ∈ ∼ R))
6		vex 2863	. . . . . 6 ⊢ y ∈ V
7	6	ideq 4871	. . . . 5 ⊢ (x I y ↔ x = y)
8		df-br 4641	. . . . 5 ⊢ (x I y ↔ ⟨x, y⟩ ∈ I )
9	7, 8	bitr3i 242	. . . 4 ⊢ (x = y ↔ ⟨x, y⟩ ∈ I )
10		df-br 4641	. . . . . 6 ⊢ (xRy ↔ ⟨x, y⟩ ∈ R)
11	10	notbii 287	. . . . 5 ⊢ (¬ xRy ↔ ¬ ⟨x, y⟩ ∈ R)
12		vex 2863	. . . . . . 7 ⊢ x ∈ V
13	12, 6	opex 4589	. . . . . 6 ⊢ ⟨x, y⟩ ∈ V
14	13	elcompl 3226	. . . . 5 ⊢ (⟨x, y⟩ ∈ ∼ R ↔ ¬ ⟨x, y⟩ ∈ R)
15	11, 14	bitr4i 243	. . . 4 ⊢ (¬ xRy ↔ ⟨x, y⟩ ∈ ∼ R)
16	9, 15	imbi12i 316	. . 3 ⊢ ((x = y → ¬ xRy) ↔ (⟨x, y⟩ ∈ I → ⟨x, y⟩ ∈ ∼ R))
17	16	2albii 1567	. 2 ⊢ (∀x∀y(x = y → ¬ xRy) ↔ ∀x∀y(⟨x, y⟩ ∈ I → ⟨x, y⟩ ∈ ∼ R))
18		equcom 1680	. . . . . 6 ⊢ (x = y ↔ y = x)
19	18	imbi1i 315	. . . . 5 ⊢ ((x = y → ¬ xRy) ↔ (y = x → ¬ xRy))
20	19	albii 1566	. . . 4 ⊢ (∀y(x = y → ¬ xRy) ↔ ∀y(y = x → ¬ xRy))
21		breq2 4644	. . . . . 6 ⊢ (y = x → (xRy ↔ xRx))
22	21	notbid 285	. . . . 5 ⊢ (y = x → (¬ xRy ↔ ¬ xRx))
23	12, 22	ceqsalv 2886	. . . 4 ⊢ (∀y(y = x → ¬ xRy) ↔ ¬ xRx)
24	20, 23	bitri 240	. . 3 ⊢ (∀y(x = y → ¬ xRy) ↔ ¬ xRx)
25	24	albii 1566	. 2 ⊢ (∀x∀y(x = y → ¬ xRy) ↔ ∀x ¬ xRx)
26	5, 17, 25	3bitr2i 264	1 ⊢ ((R ∩ I ) = ∅ ↔ ∀x ¬ xRx)

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ↔ wb 176  ∀wal 1540   = wceq 1642   ∈ wcel 1710   ∼ ccompl 3206   ∩ cin 3209   ⊆ wss 3258  ∅c0 3551  ⟨cop 4562   class class class wbr 4640   I cid 4764

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-13 1712  ax-14 1714  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334  ax-nin 4079  ax-xp 4080  ax-cnv 4081  ax-1c 4082  ax-sset 4083  ax-si 4084  ax-ins2 4085  ax-ins3 4086  ax-typlower 4087  ax-sn 4088

This proof depends on definitions:  df-bi 177  df-or 359  df-an 360  df-3or 935  df-3an 936  df-nan 1288  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-eu 2208  df-mo 2209  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2479  df-ne 2519  df-ral 2620  df-rex 2621  df-reu 2622  df-rmo 2623  df-rab 2624  df-v 2862  df-sbc 3048  df-nin 3212  df-compl 3213  df-in 3214  df-un 3215  df-dif 3216  df-symdif 3217  df-ss 3260  df-pss 3262  df-nul 3552  df-if 3664  df-pw 3725  df-sn 3742  df-pr 3743  df-uni 3893  df-int 3928  df-opk 4059  df-1c 4137  df-pw1 4138  df-uni1 4139  df-xpk 4186  df-cnvk 4187  df-ins2k 4188  df-ins3k 4189  df-imak 4190  df-cok 4191  df-p6 4192  df-sik 4193  df-ssetk 4194  df-imagek 4195  df-idk 4196  df-iota 4340  df-0c 4378  df-addc 4379  df-nnc 4380  df-fin 4381  df-lefin 4441  df-ltfin 4442  df-ncfin 4443  df-tfin 4444  df-evenfin 4445  df-oddfin 4446  df-sfin 4447  df-spfin 4448  df-phi 4566  df-op 4567  df-proj1 4568  df-proj2 4569  df-opab 4624  df-br 4641  df-id 4768

This theorem is used by: (None)