Nuprl Lemma : finite-type-product
∀[A:Type]. ∀[B:A ⟶ Type].  (finite-type(A) 
⇒ (∀a:A. finite-type(B[a])) 
⇒ finite-type(a:A × B[a]))
Proof
Definitions occuring in Statement : 
finite-type: finite-type(T)
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
product: x:A × B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
so_apply: x[s]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
exists: ∃x:A. B[x]
, 
pi1: fst(t)
, 
prop: ℙ
, 
cand: A c∧ B
, 
guard: {T}
Lemmas referenced : 
finite-type-iff-list, 
finite-type_wf, 
istype-universe, 
concat_wf, 
map_wf, 
list_wf, 
l_member_wf, 
member-concat, 
member_map
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
lambdaFormation_alt, 
cut, 
hypothesis, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
introduction, 
extract_by_obid, 
isectElimination, 
applyEquality, 
productElimination, 
independent_functionElimination, 
because_Cache, 
productEquality, 
sqequalRule, 
functionIsType, 
universeIsType, 
inhabitedIsType, 
instantiate, 
universeEquality, 
rename, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
dependent_pairEquality_alt, 
equalityIstype, 
equalityTransitivity, 
equalitySymmetry, 
productIsType, 
independent_pairFormation
Latex:
\mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].    (finite-type(A)  {}\mRightarrow{}  (\mforall{}a:A.  finite-type(B[a]))  {}\mRightarrow{}  finite-type(a:A  \mtimes{}  B[a]))
Date html generated:
2019_10_15-AM-11_13_14
Last ObjectModification:
2018_11_30-AM-10_15_12
Theory : general
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