Nuprl Lemma : bool-cmp-zero
∀[x,y:𝔹].  uiff((bool-cmp() x y) = 0 ∈ ℤ;x = y)
Proof
Definitions occuring in Statement : 
bool-cmp: bool-cmp(), 
bool: 𝔹, 
uiff: uiff(P;Q), 
uall: ∀[x:A]. B[x], 
apply: f a, 
natural_number: $n, 
int: ℤ, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
bool-cmp: bool-cmp(), 
ifthenelse: if b then t else f fi , 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
prop: ℙ, 
bfalse: ff, 
sq_type: SQType(T), 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
guard: {T}, 
true: True, 
false: False, 
not: ¬A, 
subtype_rel: A ⊆r B, 
comparison: comparison(T)
Lemmas referenced : 
btrue_wf, 
equal_wf, 
bool_wf, 
subtype_base_sq, 
int_subtype_base, 
btrue_neq_bfalse, 
bfalse_wf, 
bool-cmp_wf, 
comparison_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
unionElimination, 
thin, 
equalityElimination, 
sqequalRule, 
independent_pairFormation, 
lemma_by_obid, 
hypothesis, 
isectElimination, 
intEquality, 
natural_numberEquality, 
instantiate, 
cumulativity, 
independent_isectElimination, 
dependent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
independent_functionElimination, 
voidElimination, 
promote_hyp, 
productElimination, 
independent_pairEquality, 
isect_memberEquality, 
hypothesisEquality, 
axiomEquality, 
applyEquality, 
because_Cache, 
minusEquality, 
lambdaEquality, 
setElimination, 
rename
Latex:
\mforall{}[x,y:\mBbbB{}].    uiff((bool-cmp()  x  y)  =  0;x  =  y)
Date html generated:
2016_05_14-PM-02_37_00
Last ObjectModification:
2015_12_26-PM-04_18_06
Theory : list_1
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