Nuprl Lemma : cross-product-equal-0-iff

r:IntegDom{i}. ∀a,b:ℕ3 ⟶ |r|.
  ((∀x,y:|r|.  Dec(x y ∈ |r|))
   ((a b) 0 ∈ (ℕ3 ⟶ |r|)
     ⇐⇒ (a 0 ∈ (ℕ3 ⟶ |r|)) ∨ (b 0 ∈ (ℕ3 ⟶ |r|)) ∨ (∀l:ℕ3 ⟶ |r|. ((a l) 0 ∈ |r| ⇐⇒ (b l) 0 ∈ |r|))))


Proof




Definitions occuring in Statement :  scalar-product: (a b) cross-product: (a b) zero-vector: 0 int_seg: {i..j-} decidable: Dec(P) all: x:A. B[x] iff: ⇐⇒ Q implies:  Q or: P ∨ Q function: x:A ⟶ B[x] natural_number: $n equal: t ∈ T integ_dom: IntegDom{i} rng_zero: 0 rng_car: |r|
Definitions unfolded in proof :  so_apply: x[s] not: ¬A false: False less_than': less_than'(a;b) le: A ≤ B nat: so_lambda: λ2x.t[x] rev_implies:  Q rng: Rng crng: CRng integ_dom: IntegDom{i} uall: [x:A]. B[x] prop: member: t ∈ T and: P ∧ Q iff: ⇐⇒ Q implies:  Q all: x:A. B[x] guard: {T} or: P ∨ Q uimplies: supposing a subtype_rel: A ⊆B infix_ap: y squash: T true: True exists: x:A. B[x] integ_dom_p: IsIntegDom(r) decidable: Dec(P) sq_exists: x:A [B[x]]
Lemmas referenced :  integ_dom_wf decidable_wf rng_zero_wf le_wf false_wf scalar-product_wf iff_wf all_wf or_wf zero-vector_wf cross-product_wf rng_car_wf int_seg_wf equal_wf cross-product-equal-0 rng_times_zero iff_weakening_equal rng_times_wf squash_wf true_wf scalar-product-mul crng_times_comm cross-product-0 not_wf cross-product-non-zero-implies-ext compact-finite decidable__equal_compact_domain rng_sig_wf mul-zero-vector rng_one_wf rng_minus_wf cross-product-anti-comm vector-mul_wf
Rules used in proof :  dependent_set_memberEquality lambdaEquality sqequalRule because_Cache applyEquality functionExtensionality hypothesisEquality rename setElimination hypothesis natural_numberEquality functionEquality thin isectElimination sqequalHypSubstitution extract_by_obid introduction cut independent_pairFormation lambdaFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution inrFormation equalitySymmetry equalityTransitivity inlFormation unionElimination productElimination independent_functionElimination dependent_functionElimination independent_isectElimination baseClosed imageMemberEquality levelHypothesis equalityUniverse imageElimination applyLambdaEquality universeEquality productEquality cumulativity voidElimination

Latex:
\mforall{}r:IntegDom\{i\}.  \mforall{}a,b:\mBbbN{}3  {}\mrightarrow{}  |r|.
    ((\mforall{}x,y:|r|.    Dec(x  =  y))
    {}\mRightarrow{}  ((a  x  b)  =  0  \mLeftarrow{}{}\mRightarrow{}  (a  =  0)  \mvee{}  (b  =  0)  \mvee{}  (\mforall{}l:\mBbbN{}3  {}\mrightarrow{}  |r|.  ((a  .  l)  =  0  \mLeftarrow{}{}\mRightarrow{}  (b  .  l)  =  0))))



Date html generated: 2018_05_21-PM-09_44_10
Last ObjectModification: 2018_01_09-PM-02_07_38

Theory : matrices


Home Index