Nuprl Lemma : test-lifting
∀x:Top. (if isl(x) then 1 + outl(x) else 2 fi  ~ case x of inl(y) => 1 + y | inr(z) => 2)
Proof
Definitions occuring in Statement : 
outl: outl(x)
, 
ifthenelse: if b then t else f fi 
, 
isl: isl(x)
, 
top: Top
, 
all: ∀x:A. B[x]
, 
decide: case b of inl(x) => s[x] | inr(y) => t[y]
, 
add: n + m
, 
natural_number: $n
, 
sqequal: s ~ t
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
ifthenelse: if b then t else f fi 
, 
isl: isl(x)
, 
uall: ∀[x:A]. B[x]
, 
so_lambda: so_lambda(x,y,z,w.t[x; y; z; w])
, 
member: t ∈ T
, 
so_apply: x[s1;s2;s3;s4]
, 
so_lambda: λ2x.t[x]
, 
top: Top
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
btrue: tt
, 
outl: outl(x)
, 
strict4: strict4(F)
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
has-value: (a)↓
, 
prop: ℙ
, 
or: P ∨ Q
, 
squash: ↓T
, 
false: False
, 
bfalse: ff
Lemmas referenced : 
lifting-strict-decide, 
istype-void, 
strict4-decide, 
value-type-has-value, 
int-value-type, 
has-value_wf_base, 
istype-base, 
exception-not-value, 
is-exception_wf, 
strictness-add-right, 
top_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :lambdaFormation_alt, 
sqequalRule, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
baseClosed, 
Error :isect_memberEquality_alt, 
voidElimination, 
hypothesis, 
independent_isectElimination, 
independent_pairFormation, 
callbyvalueAdd, 
baseApply, 
closedConclusion, 
hypothesisEquality, 
productElimination, 
intEquality, 
because_Cache, 
Error :universeIsType, 
addExceptionCases, 
exceptionSqequal, 
Error :inlFormation_alt, 
imageMemberEquality, 
imageElimination, 
sqleReflexivity, 
independent_functionElimination, 
Error :inhabitedIsType, 
sqequalSqle, 
divergentSqle, 
callbyvalueDecide, 
unionElimination, 
Error :equalityIsType1, 
equalityTransitivity, 
equalitySymmetry, 
dependent_functionElimination, 
decideExceptionCases, 
axiomSqleEquality
Latex:
\mforall{}x:Top.  (if  isl(x)  then  1  +  outl(x)  else  2  fi    \msim{}  case  x  of  inl(y)  =>  1  +  y  |  inr(z)  =>  2)
Date html generated:
2019_06_20-PM-01_04_37
Last ObjectModification:
2019_06_20-PM-01_01_30
Theory : computation
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