Nuprl Lemma : absval_wf
∀[x:ℤ]. (|x| ∈ ℕ)
Proof
Definitions occuring in Statement : 
absval: |i|, 
nat: ℕ, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
int: ℤ
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
less_than: a < b, 
and: P ∧ Q, 
less_than': less_than'(a;b), 
true: True, 
squash: ↓T, 
top: Top, 
not: ¬A, 
implies: P ⇒ Q, 
false: False, 
prop: ℙ, 
nat: ℕ, 
all: ∀x:A. B[x], 
guard: {T}, 
uimplies: b supposing a, 
uiff: uiff(P;Q), 
gt: i > j, 
le: A ≤ B, 
subtype_rel: A ⊆r B
Lemmas referenced : 
absval_unfold2, 
less_than_wf, 
le_weakening2, 
le_wf, 
not-gt-2, 
add_functionality_wrt_le, 
le_reflexive, 
minus-one-mul, 
minus-one-mul-top, 
zero-add, 
add-mul-special, 
zero-mul
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
natural_numberEquality, 
lessCases, 
independent_pairFormation, 
baseClosed, 
equalityTransitivity, 
equalitySymmetry, 
imageMemberEquality, 
because_Cache, 
axiomSqEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
lambdaFormation, 
imageElimination, 
productElimination, 
independent_functionElimination, 
dependent_set_memberEquality, 
dependent_functionElimination, 
independent_isectElimination, 
axiomEquality, 
intEquality, 
minusEquality, 
multiplyEquality, 
applyEquality, 
lambdaEquality
Latex:
\mforall{}[x:\mBbbZ{}].  (|x|  \mmember{}  \mBbbN{})
Date html generated:
2019_06_20-AM-11_24_24
Last ObjectModification:
2018_08_20-PM-09_28_16
Theory : arithmetic
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