Nuprl Lemma : fpf-join-dom-decl

∀f,g:x:Id fp-> Type. ∀x:Id.  (↑x ∈ dom(f ⊕ g) ⇐⇒ (↑x ∈ dom(f)) ∨ (↑x ∈ dom(g)))


Proof




Definitions occuring in Statement :  fpf-join: f ⊕ g,  fpf-dom: x ∈ dom(f),  fpf: a:A fp-> B[a],  id-deq: IdDeq,  Id: Id,  assert: ↑b,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  or: P ∨ Q,  universe: Type
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  uall: ∀[x:A]. B[x],  so_lambda: λ2x.t[x],  so_apply: x[s],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  prop: ℙ,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  top: Top,  rev_implies: P ⇐ Q,  or: P ∨ Q
Lemmas referenced :  Id_wf,  fpf_wf,  or_wf,  assert_wf,  fpf-dom_wf,  id-deq_wf,  subtype-fpf2,  top_wf,  fpf-join-dom,  fpf-join_wf,  iff_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  lemma_by_obid,  hypothesis,  thin,  instantiate,  sqequalHypSubstitution,  isectElimination,  cumulativity,  sqequalRule,  lambdaEquality,  universeEquality,  independent_pairFormation,  hypothesisEquality,  applyEquality,  independent_isectElimination,  isect_memberEquality,  voidElimination,  voidEquality,  because_Cache,  addLevel,  productElimination,  impliesFunctionality,  dependent_functionElimination,  independent_functionElimination

Latex:
\mforall{}f,g:x:Id  fp->  Type.  \mforall{}x:Id.    (\muparrow{}x  \mmember{}  dom(f  \moplus{}  g)  \mLeftarrow{}{}\mRightarrow{}  (\muparrow{}x  \mmember{}  dom(f))  \mvee{}  (\muparrow{}x  \mmember{}  dom(g)))



Date html generated: 2018_05_21-PM-09_29_50
Last ObjectModification: 2018_02_09-AM-10_24_29

Theory : finite!partial!functions


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