Nuprl Lemma : null-map
∀[f,L:Top].  (null(map(f;L)) ~ null(L))
Proof
Definitions occuring in Statement : 
null: null(as)
, 
map: map(f;as)
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
null: null(as)
, 
map: map(f;as)
, 
list_ind: list_ind, 
has-value: (a)↓
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
cons: [a / b]
, 
bfalse: ff
, 
top: Top
, 
nil: []
, 
it: ⋅
, 
btrue: tt
Lemmas referenced : 
bottom-sqle, 
strictness-ispair, 
has-value-implies-dec-isaxiom-2, 
top_wf, 
is-exception_wf, 
has-value_wf_base, 
has-value-implies-dec-ispair-2
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
sqequalSqle, 
sqleRule, 
thin, 
divergentSqle, 
callbyvalueIspair, 
sqequalHypSubstitution, 
hypothesis, 
callbyvalueCallbyvalue, 
callbyvalueReduce, 
lemma_by_obid, 
dependent_functionElimination, 
hypothesisEquality, 
independent_functionElimination, 
unionElimination, 
sqleReflexivity, 
isectElimination, 
baseClosed, 
lambdaFormation, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
because_Cache, 
baseApply, 
closedConclusion, 
ispairExceptionCases, 
axiomSqleEquality, 
callbyvalueExceptionCases, 
exceptionSqequal, 
sqequalAxiom
Latex:
\mforall{}[f,L:Top].    (null(map(f;L))  \msim{}  null(L))
Date html generated:
2016_05_14-AM-06_30_48
Last ObjectModification:
2016_01_14-PM-08_26_06
Theory : list_0
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