Nuprl Lemma : ratreal-ratsub
∀[a,b:ℤ × ℕ+].  (ratreal(ratsub(a;b)) = (ratreal(a) - ratreal(b)))
Proof
Definitions occuring in Statement : 
ratsub: ratsub(x;y)
, 
ratreal: ratreal(r)
, 
rsub: x - y
, 
req: x = y
, 
nat_plus: ℕ+
, 
uall: ∀[x:A]. B[x]
, 
product: x:A × B[x]
, 
int: ℤ
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
sq_stable: SqStable(P)
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
squash: ↓T
Lemmas referenced : 
sq_stable__req, 
ratreal_wf, 
ratsub_wf, 
rsub_wf, 
istype-int, 
nat_plus_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
applyEquality, 
lambdaEquality_alt, 
setElimination, 
rename, 
inhabitedIsType, 
equalityTransitivity, 
equalitySymmetry, 
sqequalRule, 
independent_functionElimination, 
lambdaFormation_alt, 
because_Cache, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
equalityIstype, 
dependent_functionElimination, 
productIsType, 
universeIsType
Latex:
\mforall{}[a,b:\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}].    (ratreal(ratsub(a;b))  =  (ratreal(a)  -  ratreal(b)))
Date html generated:
2019_10_30-AM-09_25_54
Last ObjectModification:
2019_01_11-PM-00_24_49
Theory : reals
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