Nuprl Lemma : free-word-inv-append2
∀[X:Type]. ∀[x:free-word(X)].  (x + free-word-inv(x) = 0 ∈ free-word(X))
Proof
Definitions occuring in Statement : 
free-word-inv: free-word-inv(w)
, 
free-0: 0
, 
free-append: w + w'
, 
free-word: free-word(X)
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
free-word: free-word(X)
, 
all: ∀x:A. B[x]
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
cand: A c∧ B
, 
free-word-inv: free-word-inv(w)
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
uimplies: b supposing a
, 
free-append: w + w'
, 
guard: {T}
, 
free-0: 0
, 
nil: []
, 
it: ⋅
, 
word-equiv: word-equiv(X;w1;w2)
, 
exists: ∃x:A. B[x]
, 
and: P ∧ Q
, 
subtype_rel: A ⊆r B
, 
quotient: x,y:A//B[x; y]
, 
squash: ↓T
, 
true: True
, 
equiv_rel: EquivRel(T;x,y.E[x; y])
, 
refl: Refl(T;x,y.E[x; y])
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
transitive-reflexive-closure: R^*
, 
append: as @ bs
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
top: Top
, 
so_apply: x[s1;s2;s3]
, 
or: P ∨ Q
, 
infix_ap: x f y
, 
word-rel: word-rel(X;w1;w2)
, 
inverse-letters: a = -b
, 
sq_type: SQType(T)
, 
false: False
Lemmas referenced : 
word-equiv-equiv, 
list_wf, 
word-equiv_wf, 
map_wf, 
equal_wf, 
reverse_wf, 
quotient-member-eq, 
append_wf, 
nil_wf, 
transitive-reflexive-closure_wf, 
word-rel_wf, 
subtype_rel_self, 
equal-wf-base, 
squash_wf, 
true_wf, 
free-word_wf, 
last_induction, 
list_ind_nil_lemma, 
reverse_nil_lemma, 
map_nil_lemma, 
transitive-closure_wf, 
transitive-reflexive-closure_transitivity, 
cons_wf, 
transitive-reflexive-closure-base-case, 
reverse_append_sq, 
subtype_rel_list, 
top_wf, 
map_append_sq, 
reverse-cons, 
map_cons_lemma, 
list_ind_cons_lemma, 
inverse-letters_wf, 
length_wf, 
length-append, 
exists_wf, 
subtype_base_sq, 
int_subtype_base, 
or_wf, 
append_assoc_sq
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
unionEquality, 
hypothesis, 
promote_hyp, 
lambdaFormation, 
equalityTransitivity, 
equalitySymmetry, 
because_Cache, 
independent_pairFormation, 
sqequalRule, 
lambdaEquality, 
unionElimination, 
inrEquality, 
inlEquality, 
dependent_functionElimination, 
independent_functionElimination, 
independent_isectElimination, 
dependent_pairFormation, 
productEquality, 
applyEquality, 
instantiate, 
universeEquality, 
pointwiseFunctionality, 
pertypeElimination, 
productElimination, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
isect_memberEquality, 
axiomEquality, 
voidElimination, 
voidEquality, 
inlFormation, 
applyLambdaEquality, 
cumulativity, 
intEquality, 
inrFormation
Latex:
\mforall{}[X:Type].  \mforall{}[x:free-word(X)].    (x  +  free-word-inv(x)  =  0)
Date html generated:
2019_10_31-AM-07_23_34
Last ObjectModification:
2018_08_21-PM-02_02_24
Theory : free!groups
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