☰
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Piet van Blokland
©vusoft amsterdam 2013
A
B
p
A
=
=
p
B
=
=
p
=
=
A
B
p
A
- p
B
=
=
p
A
=
p
B
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+1000
A
B
p
A
p
B
90 %
95 %
99 %