Nuprl Lemma : req-int-fractions
∀[a,b:ℤ]. ∀[c,d:ℤ-o].  uiff((r(a)/r(c)) = (r(b)/r(d));(a * d) = (b * c) ∈ ℤ)
Proof
Definitions occuring in Statement : 
rdiv: (x/y)
, 
req: x = y
, 
int-to-real: r(n)
, 
int_nzero: ℤ-o
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
multiply: n * m
, 
int: ℤ
, 
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
, 
int_nzero: ℤ-o
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
nequal: a ≠ b ∈ T 
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
top: Top
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
rdiv: (x/y)
, 
req_int_terms: t1 ≡ t2
, 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
req_wf, 
rdiv_wf, 
int-to-real_wf, 
rneq-int, 
int_nzero_properties, 
full-omega-unsat, 
intformand_wf, 
intformeq_wf, 
itermVar_wf, 
itermConstant_wf, 
intformnot_wf, 
istype-int, 
int_formula_prop_and_lemma, 
istype-void, 
int_formula_prop_eq_lemma, 
int_term_value_var_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_wf, 
set_subtype_base, 
nequal_wf, 
int_subtype_base, 
req_witness, 
int_nzero_wf, 
rmul_preserves_req, 
rmul_wf, 
rinv_wf2, 
itermSubtract_wf, 
itermMultiply_wf, 
req_functionality, 
req_transitivity, 
rmul_functionality, 
req_weakening, 
rmul-rinv, 
req-iff-rsub-is-0, 
real_polynomial_null, 
real_term_value_sub_lemma, 
real_term_value_mul_lemma, 
real_term_value_var_lemma, 
real_term_value_const_lemma, 
rmul-int, 
req-int
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
independent_pairFormation, 
hypothesis, 
universeIsType, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
setElimination, 
rename, 
because_Cache, 
independent_isectElimination, 
dependent_functionElimination, 
natural_numberEquality, 
productElimination, 
independent_functionElimination, 
lambdaFormation_alt, 
approximateComputation, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
int_eqEquality, 
isect_memberEquality_alt, 
voidElimination, 
sqequalRule, 
equalityIstype, 
inhabitedIsType, 
applyEquality, 
intEquality, 
baseClosed, 
sqequalBase, 
equalitySymmetry, 
equalityTransitivity, 
baseApply, 
closedConclusion, 
independent_pairEquality, 
axiomEquality, 
isectIsTypeImplies, 
multiplyEquality
Latex:
\mforall{}[a,b:\mBbbZ{}].  \mforall{}[c,d:\mBbbZ{}\msupminus{}\msupzero{}].    uiff((r(a)/r(c))  =  (r(b)/r(d));(a  *  d)  =  (b  *  c))
Date html generated:
2019_10_29-AM-09_58_26
Last ObjectModification:
2019_01_10-PM-00_20_48
Theory : reals
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