Nuprl Lemma : equal-iff-diff-zero2

∀x,y:ℤ.  uiff(x = y ∈ ℤ;(y - x) = 0 ∈ ℤ)


Proof




Definitions occuring in Statement :  uiff: uiff(P;Q),  all: ∀x:A. B[x],  subtract: n - m,  natural_number: $n,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  member: t ∈ T,  decidable: Dec(P),  or: P ∨ Q,  uall: ∀[x:A]. B[x],  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  implies: P ⇒ Q,  not: ¬A,  top: Top,  prop: ℙ
Lemmas referenced :  subtract_wf,  equal_wf,  int_formula_prop_wf,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_term_value_subtract_lemma,  int_formula_prop_eq_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermConstant_wf,  itermVar_wf,  itermSubtract_wf,  intformeq_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__equal_int
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  independent_pairFormation,  isect_memberFormation,  cut,  lemma_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  because_Cache,  hypothesis,  unionElimination,  isectElimination,  natural_numberEquality,  independent_isectElimination,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  hypothesisEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  sqequalRule,  computeAll

Latex:
\mforall{}x,y:\mBbbZ{}.    uiff(x  =  y;(y  -  x)  =  0)



Date html generated: 2016_05_14-AM-07_20_30
Last ObjectModification: 2016_01_07-PM-03_59_58

Theory : int_2


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