Theorem isfld2 38684

Description: Obsolete theorem, use isfld 20851 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 38678	. . 3 ⊢ (𝐾 ∈ Fld → 𝐾 ∈ DivRingOps)
2		fldcrngo 38683	. . 3 ⊢ (𝐾 ∈ Fld → 𝐾 ∈ CRingOps)
3	1, 2	jca 520	. 2 ⊢ (𝐾 ∈ Fld → (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps))
4		iscrngo 38675	. . . 4 ⊢ (𝐾 ∈ CRingOps ↔ (𝐾 ∈ RingOps ∧ 𝐾 ∈ Com2))
5	4	simprbi 502	. . 3 ⊢ (𝐾 ∈ CRingOps → 𝐾 ∈ Com2)
6		elin 3920	. . . . 5 ⊢ (𝐾 ∈ (DivRingOps ∩ Com2) ↔ (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2))
7	6	biimpri 231	. . . 4 ⊢ ((𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2) → 𝐾 ∈ (DivRingOps ∩ Com2))
8		df-fld 38671	. . . 4 ⊢ Fld = (DivRingOps ∩ Com2)
9	7, 8	eleqtrrdi 2873	. . 3 ⊢ ((𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2) → 𝐾 ∈ Fld)
10	5, 9	sylan2 604	. 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 400   ∈ wcel 2142   ∩ cin 3903  RingOpscrngo 38573  DivRingOpscdrng 38627  Com2ccm2 38668  Fldcfld 38670  CRingOpsccring 38672

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1824  ax-4 1838  ax-5 1939  ax-6 1996  ax-7 2037  ax-8 2144  ax-9 2152  ax-10 2175  ax-11 2191  ax-12 2212  ax-ext 2734  ax-sep 5256  ax-nul 5268  ax-pr 5403  ax-un 7734

This proof depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1104  df-tru 1572  df-fal 1582  df-ex 1809  df-nf 1813  df-sb 2096  df-mo 2566  df-eu 2596  df-clab 2741  df-cleq 2754  df-clel 2837  df-nfc 2911  df-ne 2958  df-ral 3079  df-rex 3089  df-rab 3416  df-v 3456  df-dif 3907  df-un 3909  df-in 3911  df-ss 3921  df-nul 4286  df-if 4487  df-sn 4589  df-pr 4591  df-op 4595  df-uni 4872  df-br 5109  df-opab 5173  df-mpt 5192  df-id 5555  df-xp 5666  df-rel 5667  df-cnv 5668  df-co 5669  df-dm 5670  df-rn 5671  df-res 5672  df-iota 6492  df-fun 6538  df-fv 6544  df-1st 7984  df-2nd 7985  df-drngo 38628  df-fld 38671  df-crngo 38673

This theorem is used by:  flddmn  38737  isfldidl  38747