Nuprl Lemma : sg-inv-of-op
∀[sg:s-Group]. ∀[x,y:Point].  (x y)^-1 ≡ (y^-1 x^-1)
Proof
Definitions occuring in Statement : 
s-group: s-Group, 
sg-op: (x y), 
sg-inv: x^-1, 
ss-eq: x ≡ y, 
ss-point: Point, 
uall: ∀[x:A]. B[x]
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
ss-eq: x ≡ y, 
not: ¬A, 
implies: P ⇒ Q, 
false: False, 
subtype_rel: A ⊆r B, 
prop: ℙ, 
all: ∀x:A. B[x], 
uiff: uiff(P;Q), 
and: P ∧ Q, 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
sg-inv-unique, 
sg-op_wf, 
sg-inv_wf, 
ss-sep_wf, 
s-group_subtype1, 
ss-point_wf, 
s-group_wf, 
sg-id_wf, 
ss-eq_functionality, 
sg-assoc, 
ss-eq_weakening, 
sg-op_functionality, 
ss-eq_inversion, 
ss-eq_wf, 
uiff_transitivity, 
sg-op-inv, 
ss-eq_transitivity, 
sg-op-id
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
independent_isectElimination, 
sqequalRule, 
lambdaEquality, 
dependent_functionElimination, 
because_Cache, 
applyEquality, 
isect_memberEquality, 
voidElimination, 
independent_functionElimination, 
productElimination
Latex:
\mforall{}[sg:s-Group].  \mforall{}[x,y:Point].    (x  y)\^{}-1  \mequiv{}  (y\^{}-1  x\^{}-1)
Date html generated:
2017_10_02-PM-03_25_04
Last ObjectModification:
2017_06_22-PM-06_30_23
Theory : constructive!algebra
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