Nuprl Lemma : branch_wf
∀[P:ℙ]. ∀[d:Dec(P)]. ∀[T:Type]. ∀[A:P ⟶ T]. ∀[B:T].  (if p:P then A[p] else B fi  ∈ T)
Proof
Definitions occuring in Statement : 
branch: if p:P then A[p] else B fi 
, 
decidable: Dec(P)
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s]
, 
member: t ∈ T
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
branch: if p:P then A[p] else B fi 
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
prop: ℙ
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
so_apply: x[s]
Lemmas referenced : 
not_wf, 
equal_wf, 
decidable_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
thin, 
unionEquality, 
cumulativity, 
extract_by_obid, 
isectElimination, 
lambdaFormation, 
unionElimination, 
applyEquality, 
dependent_functionElimination, 
independent_functionElimination, 
axiomEquality, 
isect_memberEquality, 
because_Cache, 
functionEquality, 
universeEquality
Latex:
\mforall{}[P:\mBbbP{}].  \mforall{}[d:Dec(P)].  \mforall{}[T:Type].  \mforall{}[A:P  {}\mrightarrow{}  T].  \mforall{}[B:T].    (if  p:P  then  A[p]  else  B  fi    \mmember{}  T)
Date html generated:
2019_10_15-AM-11_07_10
Last ObjectModification:
2018_08_21-PM-01_58_56
Theory : general
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