Nuprl Lemma : filter-filter

[P1,P2,L:Top].  (filter(P2;filter(P1;L)) filter(λt.((P1 t) ∧b (P2 t));L))


Proof




Definitions occuring in Statement :  filter: filter(P;l) band: p ∧b q uall: [x:A]. B[x] top: Top apply: a lambda: λx.A[x] sqequal: t
Definitions unfolded in proof :  band: p ∧b q filter: filter(P;l) reduce: reduce(f;k;as) uall: [x:A]. B[x] member: t ∈ T all: x:A. B[x] list_ind: list_ind nat: implies:  Q false: False ge: i ≥  uimplies: supposing a satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] not: ¬A top: Top and: P ∧ Q prop: ifthenelse: if then else fi  cons: [a b] nil: [] it: fun_exp: f^n primrec: primrec(n;b;c) so_lambda: λ2x.t[x] so_apply: x[s] decidable: Dec(P) or: P ∨ Q nat_plus: + so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]) so_apply: x[s1;s2;s3;s4] strict4: strict4(F) has-value: (a)↓ guard: {T} squash: T subtype_rel: A ⊆B bfalse: ff
Lemmas referenced :  nat_properties satisfiable-full-omega-tt intformand_wf intformle_wf itermConstant_wf itermVar_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf ge_wf less_than_wf base_wf strictness-apply strictness-callbyvalue bottom-sqle decidable__le subtract_wf intformnot_wf itermSubtract_wf int_formula_prop_not_lemma int_term_value_subtract_lemma fun_exp_unroll_1 top_wf lifting-strict-callbyvalue has-value_wf_base is-exception_wf cbv_sqle int_subtype_base has-value-implies-dec-ispair-2 lifting-strict-ifthenelse has-value-ifthenelse-type equal_wf has-value-implies-dec-isaxiom-2 cbv_bottom_lemma
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation introduction cut thin sqequalSqle lambdaFormation fixpointLeast extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality hypothesis setElimination rename intWeakElimination natural_numberEquality independent_isectElimination dependent_pairFormation lambdaEquality int_eqEquality intEquality dependent_functionElimination isect_memberEquality voidElimination voidEquality independent_pairFormation computeAll independent_functionElimination axiomSqleEquality unionElimination dependent_set_memberEquality because_Cache sqequalAxiom baseClosed callbyvalueCallbyvalue callbyvalueReduce baseApply closedConclusion callbyvalueExceptionCases inrFormation imageMemberEquality imageElimination exceptionSqequal inlFormation applyEquality equalityTransitivity equalitySymmetry unionEquality sqleReflexivity decideExceptionCases sqleRule divergentSqle

Latex:
\mforall{}[P1,P2,L:Top].    (filter(P2;filter(P1;L))  \msim{}  filter(\mlambda{}t.((P1  t)  \mwedge{}\msubb{}  (P2  t));L))



Date html generated: 2017_04_14-AM-09_27_10
Last ObjectModification: 2017_02_27-PM-04_01_21

Theory : list_1


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