Nuprl Lemma : assert-eq_var
∀a,b:varname().  uiff(↑eq_var(a;b);a = b ∈ varname())
Proof
Definitions occuring in Statement : 
eq_var: eq_var(a;b)
, 
varname: varname()
, 
assert: ↑b
, 
uiff: uiff(P;Q)
, 
all: ∀x:A. B[x]
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
varname: varname()
, 
b-union: A ⋃ B
, 
tunion: ⋃x:A.B[x]
, 
bool: 𝔹
, 
unit: Unit
, 
ifthenelse: if b then t else f fi 
, 
pi2: snd(t)
, 
eq_var: eq_var(a;b)
, 
assert: ↑b
, 
bfalse: ff
, 
false: False
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
nat: ℕ
, 
band: p ∧b q
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
squash: ↓T
, 
true: True
, 
rev_uimplies: rev_uimplies(P;Q)
, 
btrue: tt
Lemmas referenced : 
istype-assert, 
eq_var_wf, 
assert_witness, 
varname_wf, 
assert_of_eq_atom, 
assert_wf, 
eq_atom_wf, 
bool_cases, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
eqtt_to_assert, 
band_wf, 
btrue_wf, 
eq_int_wf, 
bfalse_wf, 
equal-wf-base, 
atom_subtype_base, 
set_subtype_base, 
le_wf, 
istype-int, 
int_subtype_base, 
iff_transitivity, 
iff_weakening_uiff, 
assert_of_band, 
assert_of_eq_int, 
subtype_rel_b-union-left, 
nat_wf, 
subtype_rel_b-union-right, 
assert_functionality_wrt_uiff, 
squash_wf, 
true_wf, 
eq_atom-reflexive, 
iff_imp_equal_bool, 
iff_functionality_wrt_iff, 
iff_weakening_equal, 
istype-true, 
assert_of_tt
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
independent_pairFormation, 
isect_memberFormation_alt, 
cut, 
hypothesis, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
because_Cache, 
independent_functionElimination, 
equalityIstype, 
inhabitedIsType, 
universeIsType, 
imageElimination, 
productElimination, 
unionElimination, 
equalityElimination, 
sqequalRule, 
isatomReduceTrue, 
independent_isectElimination, 
voidElimination, 
dependent_functionElimination, 
instantiate, 
cumulativity, 
equalityTransitivity, 
equalitySymmetry, 
setElimination, 
rename, 
productEquality, 
atomEquality, 
applyEquality, 
intEquality, 
lambdaEquality_alt, 
natural_numberEquality, 
isect_memberEquality_alt, 
productIsType, 
sqequalBase, 
promote_hyp, 
independent_pairEquality, 
imageMemberEquality, 
baseClosed
Latex:
\mforall{}a,b:varname().    uiff(\muparrow{}eq\_var(a;b);a  =  b)
Date html generated:
2020_05_19-PM-09_53_00
Last ObjectModification:
2020_03_09-PM-04_07_57
Theory : terms
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