Nuprl Lemma : fun-connected_antisymmetry
∀[T:Type]. ∀[f:T ⟶ T].  ∀[x,y:T].  (x = y ∈ T) supposing (x is f*(y) and y is f*(x)) supposing retraction(T;f)
Proof
Definitions occuring in Statement : 
retraction: retraction(T;f), 
fun-connected: y is f*(x), 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
function: x:A ⟶ B[x], 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
retraction: retraction(T;f), 
exists: ∃x:A. B[x], 
prop: ℙ, 
fun-connected: y is f*(x), 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
or: P ∨ Q, 
less_than: a < b, 
squash: ↓T, 
and: P ∧ Q, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
false: False, 
not: ¬A, 
top: Top
Lemmas referenced : 
int_formula_prop_wf, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_and_lemma, 
itermVar_wf, 
intformless_wf, 
intformand_wf, 
satisfiable-full-omega-tt, 
retraction-fun-path, 
retraction_wf, 
fun-connected_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
productElimination, 
thin, 
hypothesis, 
lemma_by_obid, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
isect_memberEquality, 
axiomEquality, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
functionEquality, 
universeEquality, 
dependent_functionElimination, 
independent_functionElimination, 
independent_isectElimination, 
unionElimination, 
imageElimination, 
natural_numberEquality, 
dependent_pairFormation, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
voidElimination, 
voidEquality, 
independent_pairFormation, 
computeAll
Latex:
\mforall{}[T:Type].  \mforall{}[f:T  {}\mrightarrow{}  T].
    \mforall{}[x,y:T].    (x  =  y)  supposing  (x  is  f*(y)  and  y  is  f*(x))  supposing  retraction(T;f)
Date html generated:
2016_05_15-PM-05_07_10
Last ObjectModification:
2016_01_16-AM-11_32_44
Theory : general
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