Nuprl Lemma : star-append-iff

[T:Type]. ∀[P,Q:(T List) ⟶ ℙ].
  ∀L:T List
    (star-append(T;P;Q) ⇐⇒ (Q L) ∨ (∃L1,L2:T List. ((L (L1 L2) ∈ (T List)) ∧ (P L1) ∧ (star-append(T;P;Q) L2))))


Proof




Definitions occuring in Statement :  star-append: star-append(T;P;Q) append: as bs list: List uall: [x:A]. B[x] prop: all: x:A. B[x] exists: x:A. B[x] iff: ⇐⇒ Q or: P ∨ Q and: P ∧ Q apply: a function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  star-append: star-append(T;P;Q) uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q exists: x:A. B[x] member: t ∈ T prop: so_lambda: λ2x.t[x] so_apply: x[s] subtype_rel: A ⊆B rev_implies:  Q top: Top or: P ∨ Q concat: concat(ll) append: as bs so_lambda: so_lambda(x,y,z.t[x; y; z]) so_apply: x[s1;s2;s3] cons: [a b] guard: {T} cand: c∧ B squash: T true: True uimplies: supposing a
Lemmas referenced :  exists_wf list_wf l_all_wf2 l_member_wf equal_wf append_wf concat_wf or_wf length_wf length-append list-cases reduce_nil_lemma list_ind_nil_lemma product_subtype_list reduce_cons_lemma append_assoc l_all_cons nil_wf l_all_nil cons_wf squash_wf true_wf iff_weakening_equal
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation lambdaFormation independent_pairFormation sqequalHypSubstitution productElimination thin cut introduction extract_by_obid isectElimination cumulativity hypothesisEquality hypothesis lambdaEquality because_Cache productEquality setElimination rename applyEquality functionExtensionality setEquality applyLambdaEquality isect_memberEquality voidElimination voidEquality functionEquality universeEquality dependent_functionElimination unionElimination inlFormation hyp_replacement equalitySymmetry promote_hyp hypothesis_subsumption inrFormation dependent_pairFormation independent_functionElimination imageElimination equalityTransitivity equalityUniverse levelHypothesis natural_numberEquality imageMemberEquality baseClosed independent_isectElimination

Latex:
\mforall{}[T:Type].  \mforall{}[P,Q:(T  List)  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}L:T  List
        (star-append(T;P;Q)  L
        \mLeftarrow{}{}\mRightarrow{}  (Q  L)  \mvee{}  (\mexists{}L1,L2:T  List.  ((L  =  (L1  @  L2))  \mwedge{}  (P  L1)  \mwedge{}  (star-append(T;P;Q)  L2))))



Date html generated: 2018_05_21-PM-07_33_58
Last ObjectModification: 2017_07_26-PM-05_08_40

Theory : general


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