Nuprl Lemma : filter_cons_lemma
∀t,h,f:Top.  (filter(f;[h / t]) ~ if f h then [h / filter(f;t)] else filter(f;t) fi )
Proof
Definitions occuring in Statement : 
filter: filter(P;l)
, 
cons: [a / b]
, 
ifthenelse: if b then t else f fi 
, 
top: Top
, 
all: ∀x:A. B[x]
, 
apply: f a
, 
sqequal: s ~ t
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
filter: filter(P;l)
, 
top: Top
Lemmas referenced : 
top_wf, 
reduce_cons_lemma
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
hypothesis, 
lemma_by_obid, 
sqequalRule, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
isect_memberEquality, 
voidElimination, 
voidEquality
Latex:
\mforall{}t,h,f:Top.    (filter(f;[h  /  t])  \msim{}  if  f  h  then  [h  /  filter(f;t)]  else  filter(f;t)  fi  )
Date html generated:
2016_05_14-AM-06_49_04
Last ObjectModification:
2015_12_26-PM-00_24_03
Theory : list_0
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