Nuprl Lemma : expr_wf
∀[x:ℝ]. (expr(x) ∈ {y:ℝ| y = e^x} )
Proof
Definitions occuring in Statement : 
expr: expr(x)
, 
rexp: e^x
, 
req: x = y
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
converges-to-rexp-ext, 
subtype_rel: A ⊆r B
, 
all: ∀x:A. B[x]
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
prop: ℙ
, 
expr: expr(x)
, 
approx-rexp: approx-rexp(x;n)
, 
real: ℝ
, 
nat_plus: ℕ+
, 
less_than: a < b
, 
squash: ↓T
, 
less_than': less_than'(a;b)
, 
true: True
, 
and: P ∧ Q
, 
nequal: a ≠ b ∈ T 
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
uimplies: b supposing a
, 
sq_type: SQType(T)
, 
guard: {T}
, 
false: False
, 
has-value: (a)↓
Lemmas referenced : 
converges-to-rexp-ext, 
subtype_rel_self, 
real_wf, 
converges-to_wf, 
approx-rexp_wf, 
istype-nat, 
rexp_wf, 
req-from-converges, 
istype-less_than, 
subtype_base_sq, 
int_subtype_base, 
istype-int, 
value-type-has-value, 
int-value-type, 
req_inversion, 
req_wf, 
converges-cauchy-witness, 
cauchy-limit_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
applyEquality, 
thin, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
sqequalHypSubstitution, 
isectElimination, 
functionEquality, 
lambdaEquality_alt, 
hypothesisEquality, 
equalityTransitivity, 
equalitySymmetry, 
addEquality, 
divideEquality, 
setElimination, 
rename, 
because_Cache, 
dependent_set_memberEquality_alt, 
closedConclusion, 
natural_numberEquality, 
independent_pairFormation, 
imageMemberEquality, 
baseClosed, 
lambdaFormation_alt, 
cumulativity, 
intEquality, 
independent_isectElimination, 
dependent_functionElimination, 
independent_functionElimination, 
voidElimination, 
equalityIstype, 
sqequalBase, 
inhabitedIsType, 
callbyvalueReduce, 
axiomEquality, 
universeIsType
Latex:
\mforall{}[x:\mBbbR{}].  (expr(x)  \mmember{}  \{y:\mBbbR{}|  y  =  e\^{}x\}  )
Date html generated:
2019_10_31-AM-06_11_34
Last ObjectModification:
2019_01_30-PM-02_43_54
Theory : reals_2
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