Theorem isfld2 39048

Description: Obsolete theorem, use isfld 21002 instead. The predicate "is a field". (Contributed by Jeff Madsen, 10-Jun-2010.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
isfld2	⊢ (𝐾 ∈ Fld ↔ (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps))

Proof of Theorem isfld2

Step	Hyp	Ref	Expression
1		flddivrng 39042	. . 3 ⊢ (𝐾 ∈ Fld → 𝐾 ∈ DivRingOps)
2		fldcrngo 39047	. . 3 ⊢ (𝐾 ∈ Fld → 𝐾 ∈ CRingOps)
3	1, 2	jca 521	. 2 ⊢ (𝐾 ∈ Fld → (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps))
4		iscrngo 39039	. . . 4 ⊢ (𝐾 ∈ CRingOps ↔ (𝐾 ∈ RingOps ∧ 𝐾 ∈ Com2))
5	4	simprbi 503	. . 3 ⊢ (𝐾 ∈ CRingOps → 𝐾 ∈ Com2)
6		elin 4092	. . . . 5 ⊢ (𝐾 ∈ (DivRingOps ∩ Com2) ↔ (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2))
7	6	biimpri 231	. . . 4 ⊢ ((𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2) → 𝐾 ∈ (DivRingOps ∩ Com2))
8		df-fld 39035	. . . 4 ⊢ Fld = (DivRingOps ∩ Com2)
9	7, 8	eleqtrrdi 2871	. . 3 ⊢ ((𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2) → 𝐾 ∈ Fld)
10	5, 9	sylan2 605	. 2 ⊢ ((𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps) → 𝐾 ∈ Fld)
11	3, 10	impbii 212	1 ⊢ (𝐾 ∈ Fld ↔ (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps))

This proof depends on syntax axioms:   ↔ wb 209   ∧ wa 401   ∈ wcel 2144   ∩ cin 4088  RingOpscrngo 38937  DivRingOpscdrng 38991  Com2ccm2 39032  Fldcfld 39034  CRingOpsccring 39036

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-8 2146  ax-9 2154  ax-10 2177  ax-11 2193  ax-12 2212  ax-ext 2732  ax-sep 5248  ax-nul 5259  ax-pr 5391  ax-un 7755

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1572  df-fal 1582  df-ex 1812  df-nf 1816  df-sb 2099  df-mo 2564  df-eu 2594  df-clab 2739  df-cleq 2752  df-clel 2835  df-nfc 2909  df-ne 2956  df-ral 3077  df-rex 3087  df-rab 3413  df-v 3452  df-ss 3897  df-dif 4046  df-in 4090  df-un 4150  df-nul 4278  df-if 4482  df-sn 4585  df-pr 4587  df-op 4835  df-uni 4867  df-br 5103  df-opab 5167  df-mpt 5186  df-id 5546  df-xp 5657  df-rel 5658  df-cnv 5659  df-co 5660  df-dm 5661  df-rn 5662  df-res 5663  df-iota 6497  df-fun 6545  df-fv 6551  df-1st 8005  df-2nd 8006  df-drngo 38992  df-fld 39035  df-crngo 39037

This theorem is used by:  flddmn  39101  isfldidl  39111