Nuprl Lemma : rel-comp-exp
∀[T:Type]. ∀[R,S:T ⟶ T ⟶ ℙ].  ∀n:ℕ. (R o S)^n ⇐⇒ if (n =z 0) then λx,y. (x = y ∈ T) else (R o ((S o R)^n - 1 o S)) fi\000C 
Proof
Definitions occuring in Statement : 
rel-comp: (R1 o R2), 
rel_equivalent: R1 ⇐⇒ R2, 
rel_exp: R^n, 
nat: ℕ, 
ifthenelse: if b then t else f fi , 
eq_int: (i =z j), 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
all: ∀x:A. B[x], 
lambda: λx.A[x], 
function: x:A ⟶ B[x], 
subtract: n - m, 
natural_number: $n, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
rel_exp: R^n, 
eq_int: (i =z j), 
subtract: n - m, 
ifthenelse: if b then t else f fi , 
btrue: tt, 
implies: P ⇒ Q, 
member: t ∈ T, 
nat: ℕ, 
and: P ∧ Q, 
less_than: a < b, 
squash: ↓T, 
cand: A c∧ B, 
decidable: Dec(P), 
or: P ∨ Q, 
iff: P ⇐⇒ Q, 
not: ¬A, 
rev_implies: P ⇐ Q, 
false: False, 
uiff: uiff(P;Q), 
uimplies: b supposing a, 
top: Top, 
le: A ≤ B, 
less_than': less_than'(a;b), 
true: True, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
bfalse: ff, 
exists: ∃x:A. B[x], 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
assert: ↑b, 
nequal: a ≠ b ∈ T , 
prop: ℙ, 
so_lambda: λ2x.t[x], 
ge: i ≥ j , 
int_upper: {i...}, 
subtype_rel: A ⊆r B, 
sq_stable: SqStable(P), 
so_apply: x[s], 
rel_equivalent: R1 ⇐⇒ R2, 
infix_ap: x f y, 
rel-comp: (R1 o R2)
Lemmas referenced : 
rel_equivalent_wf, 
rel_exp_wf, 
subtract_wf, 
decidable__le, 
istype-false, 
not-le-2, 
less-iff-le, 
condition-implies-le, 
minus-one-mul, 
zero-add, 
minus-one-mul-top, 
istype-void, 
minus-add, 
minus-minus, 
add-associates, 
add-swap, 
add-commutes, 
add_functionality_wrt_le, 
add-zero, 
le-add-cancel, 
istype-le, 
rel-comp_wf, 
eq_int_wf, 
eqtt_to_assert, 
assert_of_eq_int, 
equal_wf, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
assert-bnot, 
neg_assert_of_eq_int, 
not-equal-2, 
minus-zero, 
le-add-cancel-alt, 
istype-int, 
istype-less_than, 
primrec-wf2, 
upper_subtype_nat, 
nat_properties, 
nequal-le-implies, 
sq_stable__le, 
istype-nat, 
istype-universe, 
less_than_transitivity1, 
le_weakening, 
less_than_irreflexivity, 
subtype_rel_self, 
le-add-cancel2, 
infix_ap_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
Error :lambdaFormation_alt, 
cut, 
thin, 
sqequalRule, 
rename, 
setElimination, 
Error :universeIsType, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
Error :dependent_set_memberEquality_alt, 
natural_numberEquality, 
hypothesis, 
independent_pairFormation, 
imageElimination, 
productElimination, 
dependent_functionElimination, 
unionElimination, 
voidElimination, 
independent_functionElimination, 
independent_isectElimination, 
addEquality, 
Error :isect_memberEquality_alt, 
minusEquality, 
because_Cache, 
closedConclusion, 
Error :inhabitedIsType, 
equalityElimination, 
Error :lambdaEquality_alt, 
equalityTransitivity, 
equalitySymmetry, 
Error :dependent_pairFormation_alt, 
Error :equalityIstype, 
promote_hyp, 
instantiate, 
cumulativity, 
Error :setIsType, 
hypothesis_subsumption, 
applyEquality, 
imageMemberEquality, 
baseClosed, 
Error :functionIsType, 
universeEquality, 
independent_pairEquality, 
axiomEquality, 
Error :functionIsTypeImplies, 
Error :productIsType, 
hyp_replacement, 
applyLambdaEquality, 
productEquality
Latex:
\mforall{}[T:Type].  \mforall{}[R,S:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}n:\mBbbN{}.  (R  o  S)\^{}n  \mLeftarrow{}{}\mRightarrow{}  if  (n  =\msubz{}  0)  then  \mlambda{}x,y.  (x  =  y)  else  (R  o  (rel\_exp(T;  (S  o  R);  n  -  1)  o  S))  fi 
Date html generated:
2019_06_20-PM-00_31_22
Last ObjectModification:
2019_03_27-PM-01_28_36
Theory : relations
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