Nuprl Lemma : int2nat_wf
∀[i:ℤ]. (int2nat(i) ∈ ℕ)
Proof
Definitions occuring in Statement : 
int2nat: int2nat(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, 
int2nat: int2nat(i), 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
less_than: a < b, 
less_than': less_than'(a;b), 
top: Top, 
true: True, 
squash: ↓T, 
not: ¬A, 
false: False, 
nat: ℕ, 
decidable: Dec(P), 
or: P ∨ Q, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
prop: ℙ, 
bfalse: ff, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
assert: ↑b, 
rev_implies: P ⇐ Q, 
iff: P ⇐⇒ Q
Lemmas referenced : 
lt_int_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
istype-top, 
istype-void, 
subtract_wf, 
decidable__le, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermAdd_wf, 
itermMultiply_wf, 
itermSubtract_wf, 
itermMinus_wf, 
itermVar_wf, 
intformless_wf, 
istype-int, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_add_lemma, 
int_term_value_mul_lemma, 
int_term_value_subtract_lemma, 
int_term_value_minus_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_wf, 
istype-le, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
assert-bnot, 
iff_weakening_uiff, 
assert_wf, 
less_than_wf, 
istype-less_than
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
sqequalRule, 
hypothesisEquality, 
closedConclusion, 
natural_numberEquality, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
because_Cache, 
hypothesis, 
Error :inhabitedIsType, 
Error :lambdaFormation_alt, 
unionElimination, 
equalityElimination, 
productElimination, 
independent_isectElimination, 
lessCases, 
axiomSqEquality, 
Error :isect_memberEquality_alt, 
Error :isectIsTypeImplies, 
independent_pairFormation, 
voidElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
independent_functionElimination, 
Error :dependent_set_memberEquality_alt, 
addEquality, 
multiplyEquality, 
minusEquality, 
dependent_functionElimination, 
approximateComputation, 
Error :dependent_pairFormation_alt, 
Error :lambdaEquality_alt, 
int_eqEquality, 
Error :universeIsType, 
equalityTransitivity, 
equalitySymmetry, 
Error :equalityIstype, 
promote_hyp, 
instantiate, 
cumulativity, 
axiomEquality
Latex:
\mforall{}[i:\mBbbZ{}].  (int2nat(i)  \mmember{}  \mBbbN{})
Date html generated:
2019_06_20-PM-02_52_05
Last ObjectModification:
2019_02_06-PM-06_49_52
Theory : continuity
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