Nuprl Lemma : case-real2_wf

[P:ℙ]. ∀[a,b:ℝ]. ∀[f:a ≠ b ⟶ ((↓P) ∨ (↓¬P))].  (case-real2(a;b;f) ∈ {z:ℝ(P  (z a)) ∧ ((¬P)  (z b))} )


Proof




Definitions occuring in Statement :  case-real2: case-real2(a;b;f) rneq: x ≠ y req: y real: uall: [x:A]. B[x] prop: not: ¬A squash: T implies:  Q or: P ∨ Q and: P ∧ Q member: t ∈ T set: {x:A| B[x]}  function: x:A ⟶ B[x]
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T case-real2: case-real2(a;b;f) all: x:A. B[x] real: nat: le: A ≤ B and: P ∧ Q less_than': less_than'(a;b) not: ¬A implies:  Q false: False gt: i > j or: P ∨ Q iff: ⇐⇒ Q rev_implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) uimplies: supposing a ifthenelse: if then else fi  rneq: x ≠ y rless: x < y sq_exists: x:A [B[x]] prop: bfalse: ff exists: x:A. B[x] sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b nat_plus: + decidable: Dec(P) satisfiable_int_formula: satisfiable_int_formula(fmla) top: Top subtype_rel: A ⊆B
Lemmas referenced :  case-real_wf absval_lbound subtract_wf istype-void istype-le lt_int_wf eqtt_to_assert assert_of_lt_int istype-less_than rless_wf eqff_to_assert bool_cases_sqequal subtype_base_sq bool_wf bool_subtype_base assert-bnot iff_weakening_uiff assert_wf less_than_wf nat_plus_properties decidable__lt full-omega-unsat intformand_wf intformnot_wf intformless_wf itermConstant_wf itermVar_wf istype-int int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf itermAdd_wf intformor_wf itermSubtract_wf int_term_value_add_lemma int_formula_prop_or_lemma int_term_value_subtract_lemma nat_plus_wf absval_wf rneq_wf squash_wf not_wf real_wf
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt hypothesis sqequalHypSubstitution isectElimination thin hypothesisEquality lambdaEquality_alt setElimination rename dependent_functionElimination applyEquality because_Cache dependent_set_memberEquality_alt natural_numberEquality independent_pairFormation sqequalRule lambdaFormation_alt voidElimination productElimination independent_functionElimination addEquality inhabitedIsType unionElimination equalityElimination equalityTransitivity equalitySymmetry independent_isectElimination inlEquality_alt universeIsType dependent_pairFormation_alt equalityIstype promote_hyp instantiate cumulativity inrEquality_alt approximateComputation int_eqEquality isect_memberEquality_alt minusEquality setIsType functionIsType unionIsType universeEquality

Latex:
\mforall{}[P:\mBbbP{}].  \mforall{}[a,b:\mBbbR{}].  \mforall{}[f:a  \mneq{}  b  {}\mrightarrow{}  ((\mdownarrow{}P)  \mvee{}  (\mdownarrow{}\mneg{}P))].
    (case-real2(a;b;f)  \mmember{}  \{z:\mBbbR{}|  (P  {}\mRightarrow{}  (z  =  a))  \mwedge{}  ((\mneg{}P)  {}\mRightarrow{}  (z  =  b))\}  )



Date html generated: 2019_10_29-AM-09_36_59
Last ObjectModification: 2019_05_23-PM-05_48_44

Theory : reals


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