Nuprl Lemma : filter_strong_safety

[T:Type]. ∀[P:(T List) ⟶ ℙ].  ∀f:T ⟶ 𝔹(strong_safety(T;L.P L)  strong_safety(T;L.P filter(f;L)))


Proof




Definitions occuring in Statement :  strong_safety: strong_safety(T;tr.P[tr]) filter: filter(P;l) list: List bool: 𝔹 uall: [x:A]. B[x] prop: all: x:A. B[x] implies:  Q apply: a function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  strong_safety: strong_safety(T;tr.P[tr]) uall: [x:A]. B[x] all: x:A. B[x] implies:  Q guard: {T} member: t ∈ T subtype_rel: A ⊆B so_lambda: λ2x.t[x] so_apply: x[s] prop: uimplies: supposing a iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q cand: c∧ B
Lemmas referenced :  filter_wf5 subtype_rel_dep_function bool_wf l_member_wf subtype_rel_self set_wf sublist_wf list_wf all_wf sublist_filter l_all_filter sublist_transitivity filter_is_sublist
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation lambdaFormation cut hypothesis thin sqequalHypSubstitution dependent_functionElimination introduction extract_by_obid isectElimination hypothesisEquality applyEquality lambdaEquality setEquality independent_isectElimination setElimination rename because_Cache independent_functionElimination functionEquality cumulativity universeEquality productElimination independent_pairFormation

Latex:
\mforall{}[T:Type].  \mforall{}[P:(T  List)  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}f:T  {}\mrightarrow{}  \mBbbB{}.  (strong\_safety(T;L.P  L)  {}\mRightarrow{}  strong\_safety(T;L.P  filter(f;L)))



Date html generated: 2019_10_15-AM-10_58_32
Last ObjectModification: 2018_09_17-PM-06_31_30

Theory : list!


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