Nuprl Lemma : nat-star-retract_wf
∀[s:ℕ ⟶ ℕ]. (nat-star-retract(s) ∈ ℕ*)
Proof
Definitions occuring in Statement : 
nat-star-retract: nat-star-retract(s), 
nat-star: ℕ*, 
nat: ℕ, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
function: x:A ⟶ B[x]
Definitions unfolded in proof : 
ge: i ≥ j , 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
top: Top, 
int_seg: {i..j-}, 
lelt: i ≤ j < k, 
cand: A c∧ B, 
decidable: Dec(P), 
less_than: a < b, 
squash: ↓T, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
nat-star-retract: nat-star-retract(s), 
nat: ℕ, 
so_lambda: λ2x.t[x], 
all: ∀x:A. B[x], 
prop: ℙ, 
subtype_rel: A ⊆r B, 
uimplies: b supposing a, 
le: A ≤ B, 
and: P ∧ Q, 
less_than': less_than'(a;b), 
false: False, 
not: ¬A, 
implies: P ⇒ Q, 
so_apply: x[s], 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
iff: P ⇐⇒ Q, 
guard: {T}, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
exists: ∃x:A. B[x], 
or: P ∨ Q, 
sq_type: SQType(T), 
bnot: ¬bb, 
assert: ↑b, 
rev_implies: P ⇐ Q, 
nat-star: ℕ*
Lemmas referenced : 
nat_properties, 
decidable__equal_int, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformeq_wf, 
itermVar_wf, 
intformless_wf, 
int_formula_prop_and_lemma, 
istype-void, 
int_formula_prop_not_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_wf, 
l_exists_iff, 
member_upto2, 
decidable__lt, 
bl-exists_wf, 
int_seg_wf, 
upto_wf, 
l_member_wf, 
lt_int_wf, 
nat_wf, 
int_seg_subtype_nat, 
istype-false, 
eqtt_to_assert, 
assert-bl-exists, 
l_exists_functionality, 
assert_wf, 
less_than_wf, 
iff_weakening_uiff, 
subtype_rel_set, 
assert_of_lt_int, 
le_wf, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
assert-bnot, 
l_exists_wf, 
istype-int, 
set_subtype_base, 
int_subtype_base
Rules used in proof : 
approximateComputation, 
int_eqEquality, 
Error :isect_memberEquality_alt, 
Error :productIsType, 
imageElimination, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
sqequalRule, 
Error :lambdaEquality_alt, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
setElimination, 
rename, 
because_Cache, 
hypothesis, 
Error :lambdaFormation_alt, 
hypothesisEquality, 
Error :universeIsType, 
applyEquality, 
functionExtensionality, 
independent_isectElimination, 
independent_pairFormation, 
Error :setIsType, 
Error :inhabitedIsType, 
unionElimination, 
equalityElimination, 
productElimination, 
dependent_functionElimination, 
independent_functionElimination, 
Error :dependent_set_memberEquality_alt, 
equalityTransitivity, 
equalitySymmetry, 
Error :dependent_pairFormation_alt, 
Error :equalityIsType1, 
promote_hyp, 
instantiate, 
cumulativity, 
voidElimination, 
Error :functionIsType, 
Error :equalityIsType4, 
intEquality, 
axiomEquality
Latex:
\mforall{}[s:\mBbbN{}  {}\mrightarrow{}  \mBbbN{}].  (nat-star-retract(s)  \mmember{}  \mBbbN{}*)
Date html generated:
2019_06_20-PM-03_17_41
Last ObjectModification:
2019_06_20-PM-03_12_51
Theory : continuity
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