Nuprl Lemma : ringeq-iff-rsub-is-0
∀[r:Rng]. ∀[a,b:|r|].  uiff(a = b ∈ |r|;(a +r (-r b)) = 0 ∈ |r|)
Proof
Definitions occuring in Statement : 
rng: Rng
, 
rng_minus: -r
, 
rng_zero: 0
, 
rng_plus: +r
, 
rng_car: |r|
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
infix_ap: x f y
, 
apply: f a
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
squash: ↓T
, 
rng: Rng
, 
infix_ap: x f y
, 
true: True
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
, 
prop: ℙ
Lemmas referenced : 
equal_wf, 
rng_car_wf, 
rng_plus_wf, 
rng_minus_wf, 
rng_zero_wf, 
iff_weakening_equal, 
rng_plus_inv, 
rng_properties, 
rng_wf, 
rng_plus_zero, 
squash_wf, 
true_wf, 
subtype_rel_self, 
rng_plus_assoc, 
rng_plus_comm
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
independent_pairFormation, 
applyEquality, 
thin, 
lambdaEquality_alt, 
sqequalHypSubstitution, 
imageElimination, 
extract_by_obid, 
isectElimination, 
because_Cache, 
hypothesis, 
setElimination, 
rename, 
hypothesisEquality, 
equalitySymmetry, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
equalityTransitivity, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
equalityIstype, 
inhabitedIsType, 
independent_pairEquality, 
isect_memberEquality_alt, 
axiomEquality, 
isectIsTypeImplies, 
universeIsType, 
applyLambdaEquality, 
hyp_replacement, 
lambdaEquality, 
universeEquality, 
instantiate
Latex:
\mforall{}[r:Rng].  \mforall{}[a,b:|r|].    uiff(a  =  b;(a  +r  (-r  b))  =  0)
Date html generated:
2020_05_19-PM-10_08_12
Last ObjectModification:
2020_01_08-PM-06_00_28
Theory : rings_1
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