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: ⇐⇒ 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: ⇐⇒ Q and: P ∧ Q implies:  Q prop: subtype_rel: A ⊆B uimplies: supposing a top: Top rev_implies:  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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