Nuprl Lemma : ndiff_ndiff

[a,b:ℤ]. ∀[c:ℕ].  (((a -- b) -- c) (a -- (b c)) ∈ ℤ)


Proof




Definitions occuring in Statement :  ndiff: -- b nat: uall: [x:A]. B[x] add: m int: equal: t ∈ T
Definitions unfolded in proof :  ndiff: -- b imax: imax(a;b) uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a all: x:A. B[x] implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) and: P ∧ Q ifthenelse: if then else fi  nat: bfalse: ff exists: x:A. B[x] prop: or: P ∨ Q sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b false: False not: ¬A le: A ≤ B ge: i ≥  satisfiable_int_formula: satisfiable_int_formula(fmla) top: Top squash: T subtract: m subtype_rel: A ⊆B true: True has-value: (a)↓
Lemmas referenced :  nat_wf value-type-has-value int-value-type subtract_wf le_int_wf bool_wf eqtt_to_assert assert_of_le_int eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot le_wf nat_properties satisfiable-full-omega-tt intformand_wf intformle_wf itermSubtract_wf itermConstant_wf itermVar_wf intformnot_wf itermAdd_wf int_formula_prop_and_lemma int_formula_prop_le_lemma int_term_value_subtract_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_not_lemma int_term_value_add_lemma int_formula_prop_wf ifthenelse_wf squash_wf true_wf add-associates minus-one-mul minus-add minus-one-mul-top
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation introduction cut hypothesis extract_by_obid sqequalHypSubstitution isect_memberEquality isectElimination thin hypothesisEquality axiomEquality because_Cache intEquality independent_isectElimination natural_numberEquality lambdaFormation unionElimination equalityElimination productElimination setElimination rename dependent_pairFormation equalityTransitivity equalitySymmetry promote_hyp dependent_functionElimination instantiate cumulativity independent_functionElimination voidElimination addEquality lambdaEquality int_eqEquality voidEquality independent_pairFormation computeAll applyEquality imageElimination universeEquality minusEquality imageMemberEquality baseClosed callbyvalueReduce

Latex:
\mforall{}[a,b:\mBbbZ{}].  \mforall{}[c:\mBbbN{}].    (((a  --  b)  --  c)  =  (a  --  (b  +  c)))



Date html generated: 2017_04_14-AM-09_14_58
Last ObjectModification: 2017_02_27-PM-03_52_56

Theory : int_2


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