Nuprl Lemma : sorted-by-append1

[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].  ∀x:T. ∀L:T List.  (sorted-by(R;L [x]) ⇐⇒ sorted-by(R;L) ∧ (∀z∈L.R x))


Proof




Definitions occuring in Statement :  sorted-by: sorted-by(R;L) l_all: (∀x∈L.P[x]) append: as bs cons: [a b] nil: [] list: List uall: [x:A]. B[x] prop: all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q apply: a function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T iff: ⇐⇒ Q and: P ∧ Q implies:  Q rev_implies:  Q subtype_rel: A ⊆B so_lambda: λ2x.t[x] prop: so_apply: x[s] uimplies: supposing a istype: istype(T) top: Top append: as bs so_lambda: so_lambda(x,y,z.t[x; y; z]) so_apply: x[s1;s2;s3] guard: {T}
Lemmas referenced :  sorted-by-reverse sorted-by-cons reverse-append cons_wf nil_wf append_wf sorted-by_wf subtype_rel_dep_function l_member_wf l_all_wf list_wf istype-universe reverse-cons istype-void reverse_nil_lemma list_ind_nil_lemma list_ind_cons_lemma reverse_wf l_all_iff member-reverse
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :isect_memberFormation_alt,  Error :lambdaFormation_alt,  cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality because_Cache Error :lambdaEquality_alt,  applyEquality Error :inhabitedIsType,  sqequalRule hypothesis productElimination independent_functionElimination dependent_functionElimination independent_pairFormation promote_hyp Error :universeIsType,  instantiate cumulativity functionEquality universeEquality setEquality setElimination rename equalityTransitivity equalitySymmetry Error :setIsType,  independent_isectElimination Error :productIsType,  Error :functionIsType,  Error :isect_memberEquality_alt,  voidElimination

Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}x:T.  \mforall{}L:T  List.    (sorted-by(R;L  @  [x])  \mLeftarrow{}{}\mRightarrow{}  sorted-by(R;L)  \mwedge{}  (\mforall{}z\mmember{}L.R  z  x))



Date html generated: 2019_06_20-PM-01_45_05
Last ObjectModification: 2018_10_06-PM-11_56_11

Theory : list_1


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