Nuprl Lemma : mul-minus

∀x,y:Top.  ((-x) * (-y) ~ x * y)


Proof




Definitions occuring in Statement :  top: Top,  all: ∀x:A. B[x],  multiply: n * m,  minus: -n,  sqequal: s ~ t
Definitions unfolded in proof :  top: Top,  member: t ∈ T,  all: ∀x:A. B[x],  has-value: (a)↓,  and: P ∧ Q,  implies: P ⇒ Q,  squash: ↓T,  uall: ∀[x:A]. B[x],  prop: ℙ,  subtype_rel: A ⊆r B,  true: True,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  false: False
Lemmas referenced :  istype-void,  has-value_wf_base,  squash_wf,  true_wf,  istype-base,  int_subtype_base,  subtype_rel_self,  iff_weakening_equal,  add-zero,  sqle_wf_base,  add-comm,  zero-add-sqle,  exception-not-value,  value-type-has-value,  int-value-type,  is-exception_wf,  istype-top,  mul-minus-1,  mul-minus-2,  minus-minus-sq
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberEquality_alt,  voidElimination,  cut,  introduction,  extract_by_obid,  hypothesis,  Error :lambdaFormation_alt,  sqequalRule,  thin,  sqequalSqle,  divergentSqle,  callbyvalueAdd,  sqequalHypSubstitution,  baseApply,  closedConclusion,  baseClosed,  hypothesisEquality,  productElimination,  equalityTransitivity,  equalitySymmetry,  Error :inhabitedIsType,  applyEquality,  Error :lambdaEquality_alt,  imageElimination,  isectElimination,  Error :universeIsType,  natural_numberEquality,  imageMemberEquality,  instantiate,  universeEquality,  independent_isectElimination,  independent_functionElimination,  Error :equalityIstype,  dependent_functionElimination,  callbyvalueMultiply,  because_Cache,  addExceptionCases,  axiomSqleEquality,  intEquality,  multiplyExceptionCases,  exceptionSqequal,  sqleReflexivity,  multiplyEquality

Latex:
\mforall{}x,y:Top.    ((-x)  *  (-y)  \msim{}  x  *  y)



Date html generated: 2019_06_20-AM-11_22_19
Last ObjectModification: 2019_05_21-PM-11_03_07

Theory : arithmetic


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