Nuprl Lemma : ratsub_wf
∀[a,b:ℤ × ℕ+].  (ratsub(a;b) ∈ {r:ℤ × ℕ+| ratreal(r) = (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]
, 
member: t ∈ T
, 
set: {x:A| B[x]} 
, 
product: x:A × B[x]
, 
int: ℤ
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
ratsub: ratsub(x;y)
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
rev_uimplies: rev_uimplies(P;Q)
, 
all: ∀x:A. B[x]
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
top: Top
Lemmas referenced : 
istype-int, 
nat_plus_wf, 
ratadd_wf, 
int-rat-mul_wf, 
req_wf, 
ratreal_wf, 
rsub_wf, 
radd_wf, 
rmul_wf, 
int-to-real_wf, 
int-rmul_wf, 
itermSubtract_wf, 
itermAdd_wf, 
itermVar_wf, 
itermMultiply_wf, 
itermConstant_wf, 
req-iff-rsub-is-0, 
req_functionality, 
req_transitivity, 
ratreal-ratadd, 
radd_functionality, 
ratreal-int-rat-mul, 
int-rmul-req, 
req_weakening, 
real_polynomial_null, 
real_term_value_sub_lemma, 
istype-void, 
real_term_value_add_lemma, 
real_term_value_var_lemma, 
real_term_value_mul_lemma, 
real_term_value_const_lemma
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
sqequalRule, 
sqequalHypSubstitution, 
hypothesis, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
inhabitedIsType, 
hypothesisEquality, 
isect_memberEquality_alt, 
isectElimination, 
thin, 
isectIsTypeImplies, 
productIsType, 
extract_by_obid, 
universeIsType, 
dependent_set_memberEquality_alt, 
minusEquality, 
natural_numberEquality, 
applyEquality, 
lambdaEquality_alt, 
setElimination, 
rename, 
because_Cache, 
productElimination, 
independent_isectElimination, 
dependent_functionElimination, 
approximateComputation, 
int_eqEquality, 
voidElimination
Latex:
\mforall{}[a,b:\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}].    (ratsub(a;b)  \mmember{}  \{r:\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}|  ratreal(r)  =  (ratreal(a)  -  ratreal(b))\}  )
Date html generated:
2019_10_30-AM-09_25_22
Last ObjectModification:
2019_01_11-PM-00_22_42
Theory : reals
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