Nuprl Lemma : singleton-type-product

∀[A,B:Type].  (singleton-type(A) ⇒ singleton-type(B) ⇒ singleton-type(A × B))


Proof




Definitions occuring in Statement :  singleton-type: singleton-type(A),  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  product: x:A × B[x],  universe: Type
Definitions unfolded in proof :  singleton-type: singleton-type(A),  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  exists: ∃x:A. B[x],  member: t ∈ T,  all: ∀x:A. B[x],  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T}
Lemmas referenced :  all_wf,  equal_wf,  exists_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  rename,  dependent_pairFormation,  independent_pairEquality,  hypothesisEquality,  cut,  hypothesis,  productEquality,  lemma_by_obid,  isectElimination,  lambdaEquality,  universeEquality,  dependent_functionElimination

Latex:
\mforall{}[A,B:Type].    (singleton-type(A)  {}\mRightarrow{}  singleton-type(B)  {}\mRightarrow{}  singleton-type(A  \mtimes{}  B))



Date html generated: 2016_05_14-PM-04_02_10
Last ObjectModification: 2015_12_26-PM-07_43_05

Theory : equipollence!!cardinality!


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