Nuprl Lemma : even-plus-even

[n,m:ℤ].  ↑isEven(n m) supposing (↑isEven(m)) ∧ (↑isEven(n))


Proof




Definitions occuring in Statement :  isEven: isEven(n) assert: b uimplies: supposing a uall: [x:A]. B[x] and: P ∧ Q add: m int:
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a and: P ∧ Q same-parity: same-parity(n;m) all: x:A. B[x] implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] or: P ∨ Q sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b false: False rev_implies:  Q iff: ⇐⇒ Q
Lemmas referenced :  eqtt_to_assert eqff_to_assert bool_cases_sqequal subtype_base_sq bool_wf bool_subtype_base assert_witness same-parity_wf istype-assert isEven_wf istype-int iff_weakening_uiff assert_wf isEven-add
Rules used in proof :  cut sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction sqequalHypSubstitution productElimination thin because_Cache inhabitedIsType hypothesis lambdaFormation_alt unionElimination equalityElimination extract_by_obid isectElimination independent_isectElimination sqequalRule dependent_pairFormation_alt equalityTransitivity equalitySymmetry equalityIstype hypothesisEquality promote_hyp dependent_functionElimination instantiate cumulativity independent_functionElimination voidElimination productIsType isect_memberEquality_alt isectIsTypeImplies addEquality

Latex:
\mforall{}[n,m:\mBbbZ{}].    \muparrow{}isEven(n  +  m)  supposing  (\muparrow{}isEven(m))  \mwedge{}  (\muparrow{}isEven(n))



Date html generated: 2020_05_19-PM-10_01_21
Last ObjectModification: 2019_11_27-AM-11_42_44

Theory : num_thy_1


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