Nuprl Lemma : canonical-function_wf
∀X:{X:Type| X ⊆r Base} . ∀f:ℕ ⟶ X.  (canonical-function(f) ∈ {g:Base| g = f ∈ (ℕ ⟶ X)} )
Proof
Definitions occuring in Statement : 
canonical-function: canonical-function(f), 
nat: ℕ, 
subtype_rel: A ⊆r B, 
all: ∀x:A. B[x], 
member: t ∈ T, 
set: {x:A| B[x]} , 
function: x:A ⟶ B[x], 
base: Base, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
canonical-function: canonical-function(f), 
prop: ℙ, 
has-value: (a)↓, 
and: P ∧ Q, 
implies: P ⇒ Q, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(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, 
bfalse: ff, 
exists: ∃x:A. B[x], 
or: P ∨ Q, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
assert: ↑b, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
nat: ℕ, 
gt: i > j
Lemmas referenced : 
nat_wf, 
subtype_rel_wf, 
base_wf, 
equal-wf-base, 
lt_int_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
istype-top, 
istype-void, 
bottom-sqle, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
iff_transitivity, 
assert_wf, 
bnot_wf, 
not_wf, 
less_than_wf, 
iff_weakening_uiff, 
assert_of_bnot, 
not-gt-2, 
le_wf, 
has-value_wf_base, 
is-exception_wf, 
exception-not-value, 
value-type-has-value, 
int-value-type, 
less_than_transitivity1, 
less_than_irreflexivity, 
bool_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :lambdaFormation_alt, 
cut, 
setElimination, 
thin, 
rename, 
sqequalHypSubstitution, 
hypothesis, 
Error :functionIsType, 
Error :universeIsType, 
introduction, 
extract_by_obid, 
hypothesisEquality, 
Error :setIsType, 
universeEquality, 
isectElimination, 
pointwiseFunctionality, 
sqequalRule, 
baseApply, 
closedConclusion, 
baseClosed, 
because_Cache, 
sqequalSqle, 
divergentSqle, 
callbyvalueLess, 
productElimination, 
Error :inhabitedIsType, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
lessCases, 
Error :isect_memberFormation_alt, 
axiomSqEquality, 
Error :isect_memberEquality_alt, 
independent_pairFormation, 
voidElimination, 
natural_numberEquality, 
imageMemberEquality, 
imageElimination, 
independent_functionElimination, 
Error :dependent_pairFormation_alt, 
Error :equalityIsType2, 
promote_hyp, 
dependent_functionElimination, 
instantiate, 
applyEquality, 
Error :dependent_set_memberEquality_alt, 
Error :equalityIsType1, 
cumulativity, 
sqleReflexivity, 
lessExceptionCases, 
axiomSqleEquality, 
intEquality, 
exceptionSqequal, 
functionExtensionality
Latex:
\mforall{}X:\{X:Type|  X  \msubseteq{}r  Base\}  .  \mforall{}f:\mBbbN{}  {}\mrightarrow{}  X.    (canonical-function(f)  \mmember{}  \{g:Base|  g  =  f\}  )
Date html generated:
2019_06_20-AM-11_28_10
Last ObjectModification:
2018_09_29-PM-11_20_57
Theory : call!by!value_2
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