Nuprl Lemma : not-not-finite-xmiddle

[T:Type]. (finite(T)  (∀P:T ⟶ ℙ(¬¬(∀i:T. (P[i] ∨ P[i]))))))


Proof




Definitions occuring in Statement :  finite: finite(T) uall: [x:A]. B[x] prop: so_apply: x[s] all: x:A. B[x] not: ¬A implies:  Q or: P ∨ Q function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T implies:  Q finite: finite(T) exists: x:A. B[x] nat: prop: equipollent: B biject: Bij(A;B;f) and: P ∧ Q
Lemmas referenced :  not-not-finite-xmiddle-1 int_seg_wf surject_wf finite_wf istype-universe equipollent_inversion
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt hypothesis sqequalHypSubstitution isectElimination thin hypothesisEquality lambdaFormation_alt independent_functionElimination productElimination dependent_pairFormation_alt sqequalRule productIsType functionIsType universeIsType natural_numberEquality setElimination rename because_Cache instantiate universeEquality

Latex:
\mforall{}[T:Type].  (finite(T)  {}\mRightarrow{}  (\mforall{}P:T  {}\mrightarrow{}  \mBbbP{}.  (\mneg{}\mneg{}(\mforall{}i:T.  (P[i]  \mvee{}  (\mneg{}P[i]))))))



Date html generated: 2020_05_19-PM-10_00_48
Last ObjectModification: 2019_10_24-AM-10_45_45

Theory : equipollence!!cardinality!


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