Nuprl Lemma : lsum_nil_lemma
∀f:Top. (Σ(f[x] | x ∈ []) ~ 0)
Proof
Definitions occuring in Statement : 
lsum: Σ(f[x] | x ∈ L)
, 
nil: []
, 
top: Top
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
natural_number: $n
, 
sqequal: s ~ t
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
lsum: Σ(f[x] | x ∈ L)
, 
member: t ∈ T
, 
top: Top
Lemmas referenced : 
istype-top, 
map_nil_lemma, 
istype-void, 
l_sum_nil_lemma
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
hypothesis, 
introduction, 
extract_by_obid, 
sqequalRule, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
isect_memberEquality_alt, 
voidElimination
Latex:
\mforall{}f:Top.  (\mSigma{}(f[x]  |  x  \mmember{}  [])  \msim{}  0)
Date html generated:
2020_05_19-PM-09_46_45
Last ObjectModification:
2019_11_12-PM-11_19_24
Theory : list_1
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