Nuprl Lemma : multiply_nat_plus_iff
∀[i:ℕ+]. ∀[x:ℤ].  (i * x ∈ ℕ 
⇐⇒ x ∈ ℕ)
Proof
Definitions occuring in Statement : 
nat_plus: ℕ+
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
, 
iff: P 
⇐⇒ Q
, 
member: t ∈ T
, 
multiply: n * m
, 
int: ℤ
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
subtype_rel: A ⊆r B
, 
nat_plus: ℕ+
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
rev_implies: P 
⇐ Q
, 
nat: ℕ
, 
all: ∀x:A. B[x]
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
exists: ∃x:A. B[x]
, 
top: Top
, 
ge: i ≥ j 
, 
subtract: n - m
, 
uiff: uiff(P;Q)
, 
less_than: a < b
, 
squash: ↓T
, 
less_than': less_than'(a;b)
, 
true: True
, 
le: A ≤ B
, 
not: ¬A
, 
false: False
Lemmas referenced : 
istype-nat, 
int_subtype_base, 
set_subtype_base, 
less_than_wf, 
mul_bounds_1a, 
nat_plus_subtype_nat, 
istype-le, 
istype-int, 
nat_plus_wf, 
nat_plus_properties, 
nat_properties, 
decidable__le, 
mul_bounds_1b, 
istype-less_than, 
minus-one-mul, 
subtract_wf, 
subtype_base_sq, 
istype-sqequal, 
le_weakening2, 
mul-swap, 
istype-void, 
add_functionality_wrt_le, 
le_reflexive, 
minus-one-mul-top, 
zero-add, 
one-mul, 
add-mul-special, 
add-associates, 
two-mul, 
add-commutes, 
mul-distributes-right, 
zero-mul, 
less-iff-le, 
mul-associates, 
add-swap, 
add-zero, 
omega-shadow, 
not-lt-2, 
minus-zero, 
not-le-2, 
istype-false, 
decidable__lt
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
independent_pairFormation, 
Error :lambdaFormation_alt, 
sqequalHypSubstitution, 
hypothesis, 
sqequalRule, 
Error :equalityIstype, 
extract_by_obid, 
baseApply, 
closedConclusion, 
baseClosed, 
hypothesisEquality, 
applyEquality, 
isectElimination, 
thin, 
intEquality, 
Error :lambdaEquality_alt, 
natural_numberEquality, 
Error :inhabitedIsType, 
independent_isectElimination, 
because_Cache, 
sqequalBase, 
equalitySymmetry, 
Error :dependent_set_memberEquality_alt, 
multiplyEquality, 
setElimination, 
rename, 
equalityTransitivity, 
productElimination, 
independent_pairEquality, 
dependent_functionElimination, 
axiomEquality, 
Error :functionIsTypeImplies, 
Error :isect_memberEquality_alt, 
Error :isectIsTypeImplies, 
Error :universeIsType, 
applyLambdaEquality, 
unionElimination, 
minusEquality, 
addEquality, 
instantiate, 
cumulativity, 
independent_functionElimination, 
Error :dependent_pairFormation_alt, 
promote_hyp, 
voidElimination, 
imageMemberEquality
Latex:
\mforall{}[i:\mBbbN{}\msupplus{}].  \mforall{}[x:\mBbbZ{}].    (i  *  x  \mmember{}  \mBbbN{}  \mLeftarrow{}{}\mRightarrow{}  x  \mmember{}  \mBbbN{})
Date html generated:
2019_06_20-AM-11_26_47
Last ObjectModification:
2018_12_11-PM-01_01_39
Theory : arithmetic
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