(8steps total)
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IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
Bijections have inverses.
At:
bij
imp
exists
inv2
A
,
B
:Type,
f
:(
A
B
). Bij(
A
;
B
;
f
)
(
g
:(
B
A
). InvFuns(
A
;
B
;
f
;
g
))
By:
Repeat Def of InvFuns(
A
;
B
;
f
;
g
) | Bij(
A
;
B
;
f
) | Inj(
A
;
B
;
f
) | Surj(
A
;
B
;
f
)
Generated subgoal:
1
1.
A
: Type
2.
B
: Type
3.
f
:
A
B
4.
a1
,
a2
:
A
.
f
(
a1
) =
f
(
a2
)
a1
=
a2
5.
b
:
B
.
a
:
A
.
f
(
a
) =
b
g
:(
B
A
). (
x
:
A
.
g
(
f
(
x
)) =
x
) & (
y
:
B
.
f
(
g
(
y
)) =
y
)
7
steps
About:
IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
(8steps total)
PrintForm
Definitions
DiscreteMath
Sections
DiscrMathExt
Doc