Nuprl Lemma : Wadd-assoc
∀[A:Type]. ∀[B:A ⟶ Type]. ∀[zero:A ⟶ 𝔹]. ∀[w3,w2,w1:W(A;a.B[a])].  ((w1 + (w2 + w3)) = ((w1 + w2) + w3) ∈ W(A;a.B[a]))
Proof
Definitions occuring in Statement : 
Wadd: (w1 + w2), 
W: W(A;a.B[a]), 
bool: 𝔹, 
uall: ∀[x:A]. B[x], 
so_apply: x[s], 
function: x:A ⟶ B[x], 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
implies: P ⇒ Q, 
all: ∀x:A. B[x], 
Wadd: (w1 + w2), 
Wsup: Wsup(a;b), 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
exists: ∃x:A. B[x], 
prop: ℙ, 
or: P ∨ Q, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
assert: ↑b, 
false: False, 
not: ¬A, 
squash: ↓T, 
true: True, 
subtype_rel: A ⊆r B, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q
Lemmas referenced : 
W-induction, 
all_wf, 
equal_wf, 
Wadd_wf, 
bool_wf, 
eqtt_to_assert, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
W_wf, 
Wsup_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
applyEquality, 
functionExtensionality, 
cumulativity, 
because_Cache, 
hypothesis, 
independent_functionElimination, 
lambdaFormation, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
independent_isectElimination, 
dependent_pairFormation, 
promote_hyp, 
dependent_functionElimination, 
instantiate, 
voidElimination, 
functionEquality, 
isect_memberEquality, 
axiomEquality, 
imageElimination, 
universeEquality, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed
Latex:
\mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].  \mforall{}[zero:A  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[w3,w2,w1:W(A;a.B[a])].
    ((w1  +  (w2  +  w3))  =  ((w1  +  w2)  +  w3))
Date html generated:
2017_04_14-AM-07_44_22
Last ObjectModification:
2017_02_27-PM-03_15_09
Theory : co-recursion
Home
Index