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: List uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] implies:  Q apply: a function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a so_lambda: λ2x.t[x] implies:  Q prop: so_apply: x[s] all: x:A. B[x] top: Top squash: T guard: {T} iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q or: P ∨ Q true: True subtype_rel: A ⊆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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