Nuprl Lemma : not-even-succ-implies-even
∀n:ℤ. ((¬↑isEven(n + 1)) ⇒ (↑isEven(n)))
Proof
Definitions occuring in Statement : 
isEven: isEven(n), 
assert: ↑b, 
all: ∀x:A. B[x], 
not: ¬A, 
implies: P ⇒ Q, 
add: n + m, 
natural_number: $n, 
int: ℤ
Definitions unfolded in proof : 
isEven: isEven(n), 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
subtype_rel: A ⊆r B, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
rev_uimplies: rev_uimplies(P;Q), 
squash: ↓T, 
prop: ℙ, 
true: True, 
guard: {T}, 
iff: P ⇐⇒ Q, 
nat_plus: ℕ+, 
less_than: a < b, 
less_than': less_than'(a;b), 
nequal: a ≠ b ∈ T , 
decidable: Dec(P), 
or: P ∨ Q, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
false: False, 
not: ¬A, 
top: Top, 
int_nzero: ℤ-o, 
sq_type: SQType(T)
Lemmas referenced : 
equal_wf, 
int_subtype_base, 
subtype_base_sq, 
eq_int_wf, 
assert_wf, 
not_wf, 
int_formula_prop_wf, 
int_term_value_subtract_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_less_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_eq_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_and_lemma, 
itermSubtract_wf, 
intformle_wf, 
intformless_wf, 
itermConstant_wf, 
itermVar_wf, 
intformeq_wf, 
intformnot_wf, 
intformand_wf, 
satisfiable-full-omega-tt, 
decidable__equal_int, 
less_than_wf, 
mod_bounds, 
iff_weakening_equal, 
add-one-mod-2, 
true_wf, 
squash_wf, 
nequal_wf, 
assert_of_eq_int, 
modulus_wf, 
neg_assert_of_eq_int
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
lambdaFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
because_Cache, 
hypothesis, 
applyEquality, 
natural_numberEquality, 
productElimination, 
independent_isectElimination, 
lambdaEquality, 
imageElimination, 
hypothesisEquality, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
intEquality, 
imageMemberEquality, 
baseClosed, 
independent_functionElimination, 
dependent_set_memberEquality, 
independent_pairFormation, 
introduction, 
dependent_functionElimination, 
unionElimination, 
dependent_pairFormation, 
int_eqEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
addEquality, 
addLevel, 
instantiate, 
cumulativity
Latex:
\mforall{}n:\mBbbZ{}.  ((\mneg{}\muparrow{}isEven(n  +  1))  {}\mRightarrow{}  (\muparrow{}isEven(n)))
Date html generated:
2016_05_14-PM-04_23_40
Last ObjectModification:
2016_01_14-PM-11_38_11
Theory : num_thy_1
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