Nuprl Lemma : p-fun-exp-one
∀[A:Type]. ∀[f:A ⟶ (A + Top)].  (f^1 = f ∈ (A ⟶ (A + Top)))
Proof
Definitions occuring in Statement : 
p-fun-exp: f^n
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
function: x:A ⟶ B[x]
, 
union: left + right
, 
natural_number: $n
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
p-fun-exp: f^n
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
top: Top
, 
uall: ∀[x:A]. B[x]
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
primrec1_lemma, 
equal_wf, 
squash_wf, 
true_wf, 
top_wf, 
p-compose-id, 
iff_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hypothesis, 
isect_memberFormation, 
applyEquality, 
lambdaEquality, 
imageElimination, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
functionEquality, 
cumulativity, 
unionEquality, 
because_Cache, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
axiomEquality
Latex:
\mforall{}[A:Type].  \mforall{}[f:A  {}\mrightarrow{}  (A  +  Top)].    (f\^{}1  =  f)
Date html generated:
2017_10_01-AM-09_14_25
Last ObjectModification:
2017_07_26-PM-04_49_32
Theory : general
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