Nuprl Lemma : finite-type-union
∀[A,B:Type].  (finite-type(A) 
⇒ finite-type(B) 
⇒ finite-type(A + B))
Proof
Definitions occuring in Statement : 
finite-type: finite-type(T)
, 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
union: left + right
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
exists: ∃x:A. B[x]
, 
all: ∀x:A. B[x]
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
or: P ∨ Q
, 
cand: A c∧ B
, 
guard: {T}
Lemmas referenced : 
finite-type-iff-list, 
append_wf, 
map_wf, 
member_append, 
member_map, 
l_member_wf, 
or_wf, 
exists_wf, 
and_wf, 
equal_wf, 
all_wf, 
finite-type_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
productElimination, 
independent_functionElimination, 
unionEquality, 
dependent_pairFormation, 
lambdaEquality, 
inlEquality, 
inrEquality, 
because_Cache, 
dependent_functionElimination, 
addLevel, 
orFunctionality, 
sqequalRule, 
universeEquality, 
unionElimination, 
inlFormation, 
independent_pairFormation, 
inrFormation
Latex:
\mforall{}[A,B:Type].    (finite-type(A)  {}\mRightarrow{}  finite-type(B)  {}\mRightarrow{}  finite-type(A  +  B))
Date html generated:
2016_05_15-PM-04_26_24
Last ObjectModification:
2015_12_27-PM-02_51_16
Theory : general
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