Theorem isfld2 38714

Description: Obsolete theorem, use isfld 20890 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 38708	. . 3 ⊢ (𝐾 ∈ Fld → 𝐾 ∈ DivRingOps)
2		fldcrngo 38713	. . 3 ⊢ (𝐾 ∈ Fld → 𝐾 ∈ CRingOps)
3	1, 2	jca 521	. 2 ⊢ (𝐾 ∈ Fld → (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps))
4		iscrngo 38705	. . . 4 ⊢ (𝐾 ∈ CRingOps ↔ (𝐾 ∈ RingOps ∧ 𝐾 ∈ Com2))
5	4	simprbi 503	. . 3 ⊢ (𝐾 ∈ CRingOps → 𝐾 ∈ Com2)
6		elin 3922	. . . . 5 ⊢ (𝐾 ∈ (DivRingOps ∩ Com2) ↔ (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2))
7	6	biimpri 231	. . . 4 ⊢ ((𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2) → 𝐾 ∈ (DivRingOps ∩ Com2))
8		df-fld 38701	. . . 4 ⊢ Fld = (DivRingOps ∩ Com2)
9	7, 8	eleqtrrdi 2876	. . 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 2146   ∩ cin 3905  RingOpscrngo 38603  DivRingOpscdrng 38657  Com2ccm2 38698  Fldcfld 38700  CRingOpsccring 38702

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2148  ax-9 2156  ax-10 2179  ax-11 2195  ax-12 2216  ax-ext 2737  ax-sep 5259  ax-nul 5271  ax-pr 5406  ax-un 7742

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  df-mo 2569  df-eu 2599  df-clab 2744  df-cleq 2757  df-clel 2840  df-nfc 2914  df-ne 2961  df-ral 3082  df-rex 3092  df-rab 3419  df-v 3459  df-dif 3909  df-un 3911  df-in 3913  df-ss 3923  df-nul 4287  df-if 4490  df-sn 4592  df-pr 4594  df-op 4598  df-uni 4875  df-br 5112  df-opab 5176  df-mpt 5195  df-id 5558  df-xp 5669  df-rel 5670  df-cnv 5671  df-co 5672  df-dm 5673  df-rn 5674  df-res 5675  df-iota 6496  df-fun 6542  df-fv 6548  df-1st 7992  df-2nd 7993  df-drngo 38658  df-fld 38701  df-crngo 38703

This theorem is used by:  flddmn  38767  isfldidl  38777