Nuprl Lemma : p-first-cons
∀[A,B:Type]. ∀[L:(A ⟶ (B + Top)) List]. ∀[f:A ⟶ (B + Top)].  (p-first([f / L]) = [f?p-first(L)] ∈ (A ⟶ (B + Top)))
Proof
Definitions occuring in Statement : 
p-conditional: [f?g]
, 
p-first: p-first(L)
, 
cons: [a / b]
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
function: x:A ⟶ B[x]
, 
union: left + right
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
append: as @ bs
, 
all: ∀x:A. B[x]
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
top: Top
, 
so_apply: x[s1;s2;s3]
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
list_ind_cons_lemma, 
list_ind_nil_lemma, 
top_wf, 
list_wf, 
equal_wf, 
squash_wf, 
true_wf, 
p-first-append, 
cons_wf, 
nil_wf, 
p-conditional_wf, 
p-first_wf, 
iff_weakening_equal, 
p-first-singleton, 
p-conditional-to-p-first
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hypothesis, 
functionEquality, 
cumulativity, 
hypothesisEquality, 
unionEquality, 
isectElimination, 
axiomEquality, 
because_Cache, 
universeEquality, 
applyEquality, 
lambdaEquality, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
functionExtensionality, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
productElimination, 
independent_functionElimination
Latex:
\mforall{}[A,B:Type].  \mforall{}[L:(A  {}\mrightarrow{}  (B  +  Top))  List].  \mforall{}[f:A  {}\mrightarrow{}  (B  +  Top)].    (p-first([f  /  L])  =  [f?p-first(L)])
Date html generated:
2018_05_21-PM-06_44_28
Last ObjectModification:
2017_07_26-PM-04_55_07
Theory : general
Home
Index