Nuprl Lemma : trivial_map
∀[T:Type]. ∀[a:T List]. ∀[f:T ⟶ T].  map(f;a) = a ∈ (T List) supposing ∀x:T. ((x ∈ a) 
⇒ ((f x) = x ∈ T))
Proof
Definitions occuring in Statement : 
l_member: (x ∈ l)
, 
map: map(f;as)
, 
list: T List
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
so_lambda: λ2x.t[x]
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
top: Top
, 
squash: ↓T
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
or: P ∨ Q
, 
true: True
, 
subtype_rel: A ⊆r B
Lemmas referenced : 
list_induction, 
all_wf, 
l_member_wf, 
equal_wf, 
list_wf, 
map_wf, 
map_nil_lemma, 
nil_wf, 
map_cons_lemma, 
squash_wf, 
true_wf, 
cons_wf, 
cons_member, 
iff_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
functionEquality, 
cumulativity, 
hypothesis, 
applyEquality, 
functionExtensionality, 
independent_functionElimination, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
lambdaFormation, 
rename, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
because_Cache, 
productElimination, 
inrFormation, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
universeEquality, 
inlFormation, 
axiomEquality
Latex:
\mforall{}[T:Type].  \mforall{}[a:T  List].  \mforall{}[f:T  {}\mrightarrow{}  T].    map(f;a)  =  a  supposing  \mforall{}x:T.  ((x  \mmember{}  a)  {}\mRightarrow{}  ((f  x)  =  x))
Date html generated:
2017_04_14-AM-08_54_22
Last ObjectModification:
2017_02_27-PM-03_38_47
Theory : list_0
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