Nuprl Lemma : polymorphic-constant
∀[T:Type]. ∀f:⋂A:Type. (A ⟶ T). ∃t:T. ∀A:Type. ∀x:A.  ((f x) = t ∈ T) supposing mono(T) ∧ value-type(T)
Proof
Definitions occuring in Statement : 
mono: mono(T), 
value-type: value-type(T), 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
and: P ∧ Q, 
apply: f a, 
isect: ⋂x:A. B[x], 
function: x:A ⟶ B[x], 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
uimplies: b supposing a, 
member: t ∈ T, 
and: P ∧ Q, 
mono: mono(T), 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
prop: ℙ, 
value-type: value-type(T), 
has-value: (a)↓, 
cand: A c∧ B, 
exists: ∃x:A. B[x], 
so_lambda: λ2x.t[x], 
subtype_rel: A ⊆r B, 
so_apply: x[s], 
squash: ↓T, 
true: True, 
guard: {T}, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q
Lemmas referenced : 
is-above_wf, 
base_wf, 
equal-wf-base, 
polymorphic-constant-base, 
all_wf, 
equal_wf, 
mono_wf, 
value-type_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
introduction, 
sqequalRule, 
sqequalHypSubstitution, 
productElimination, 
thin, 
independent_pairEquality, 
lambdaEquality, 
dependent_functionElimination, 
hypothesisEquality, 
axiomEquality, 
hypothesis, 
extract_by_obid, 
isectElimination, 
cumulativity, 
isect_memberEquality, 
axiomSqleEquality, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
rename, 
lambdaFormation, 
independent_isectElimination, 
independent_pairFormation, 
dependent_pairFormation, 
universeEquality, 
instantiate, 
applyEquality, 
isectEquality, 
functionEquality, 
productEquality, 
pointwiseFunctionalityForEquality, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_functionElimination
Latex:
\mforall{}[T:Type].  \mforall{}f:\mcap{}A:Type.  (A  {}\mrightarrow{}  T).  \mexists{}t:T.  \mforall{}A:Type.  \mforall{}x:A.    ((f  x)  =  t)  supposing  mono(T)  \mwedge{}  value-type(T)
Date html generated:
2018_05_21-PM-01_11_39
Last ObjectModification:
2018_05_01-PM-04_36_51
Theory : num_thy_1
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