Nuprl Lemma : contravariance-general
11,40
postcript
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A
,
A'
:Type{i},
B
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A
Type{j}),
f
:(
x
:
A
B
(
x
)). (
A'
r
A
)
(
f
x
:
A'
B
(
x
))
latex
Definitions
x
:
A
B
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t
T
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x
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A
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B
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Type
origin
A, A':Type{i}, B:(A
Type{j}), f:(x:AB(x)). (A' 
r A) 
(f 
x:A'B(x)) A, A':Type{i}, B:(AType{j}), f:(x:AB(x)). (A' r A) (f x:A'B(x)) B(x) Tx:A. B(x) T Q