Nuprl Lemma : symmetric_rel_or

∀[T:Type]. ∀[R1,R2:T ⟶ T ⟶ ℙ].  (Sym(T;x,y.x R1 y) ⇒ Sym(T;x,y.x R2 y) ⇒ Sym(T;x,y.x (R1 ∨ R2) y))


Proof




Definitions occuring in Statement :  rel_or: R1 ∨ R2,  sym: Sym(T;x,y.E[x; y]),  uall: ∀[x:A]. B[x],  prop: ℙ,  infix_ap: x f y,  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  rel_or: R1 ∨ R2,  sym: Sym(T;x,y.E[x; y]),  infix_ap: x f y,  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  all: ∀x:A. B[x],  or: P ∨ Q,  member: t ∈ T,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T}
Lemmas referenced :  or_wf,  all_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  Error :isect_memberFormation_alt,  lambdaFormation,  sqequalHypSubstitution,  unionElimination,  thin,  inlFormation,  applyEquality,  hypothesisEquality,  inrFormation,  cut,  introduction,  extract_by_obid,  isectElimination,  hypothesis,  lambdaEquality,  functionEquality,  Error :inhabitedIsType,  Error :functionIsType,  Error :universeIsType,  universeEquality,  dependent_functionElimination,  independent_functionElimination

Latex:
\mforall{}[T:Type].  \mforall{}[R1,R2:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    (Sym(T;x,y.x  R1  y)  {}\mRightarrow{}  Sym(T;x,y.x  R2  y)  {}\mRightarrow{}  Sym(T;x,y.x  (R1  \mvee{}  R2)  y))



Date html generated: 2019_06_20-PM-00_31_09
Last ObjectModification: 2018_09_26-PM-00_44_10

Theory : relations


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