Nuprl Lemma : tf-apply_wf
∀[A:Type]. ∀[a:A]. ∀[B:type-function{i:l}(A)].  (tf-apply(B;a) ∈ Type)
Proof
Definitions occuring in Statement : 
tf-apply: tf-apply(f;x)
, 
type-function: type-function{i:l}(A)
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
type-function: type-function{i:l}(A)
, 
tf-apply: tf-apply(f;x)
, 
member: t ∈ T
, 
per-function: per-function(A;a.B[a])
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
base-type-family: base-type-family{i:l}(A;a.B[a])
, 
implies: P 
⇒ Q
, 
guard: {T}
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
Lemmas referenced : 
type-function_wf, 
istype-universe, 
function-eq-implies, 
function-eq_wf, 
member_wf, 
squash_wf, 
true_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
sqequalHypSubstitution, 
Error :universeIsType, 
cut, 
introduction, 
extract_by_obid, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
universeEquality, 
pointwiseFunctionality, 
sqequalRule, 
pertypeElimination, 
instantiate, 
cumulativity, 
baseClosed, 
independent_isectElimination, 
Error :equalityIsType4, 
Error :inhabitedIsType, 
Error :isect_memberEquality_alt, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
because_Cache, 
independent_functionElimination, 
applyEquality, 
Error :lambdaEquality_alt, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality
Latex:
\mforall{}[A:Type].  \mforall{}[a:A].  \mforall{}[B:type-function\{i:l\}(A)].    (tf-apply(B;a)  \mmember{}  Type)
Date html generated:
2019_06_20-AM-11_30_01
Last ObjectModification:
2018_10_06-AM-10_08_45
Theory : per!type
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