4. State →
State Int
String State Int String
State Int
Int State Int Int
State Int
MyType State Int MyType
State Int
Maybe Bool State Int (Maybe Bool)
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5. State Int
String State Int String
quot;ABCquot;
quot;12345quot;
quot;hogequot; State Int
Int State Int Int
236
8974
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6. State
State Int
String State Int String
quot;ABCquot; ???
quot;12345quot; ???
quot;hogequot; State Int ???
Int State Int Int
236 ???
8974 ???
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15. return State
State Int
String return State Int String
quot;ABCquot; ???
quot;12345quot; ???
State Int ???
Int return State Int Int
236 ???
???
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16. State Int
String return State Int String
quot;ABCquot; ???
quot;12345quot; ???
State Int ???
Int return State Int Int
236 ???
???
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17. State
State Int
String return State Int String
quot;ABCquot; (“ABC”, s0)
quot;12345quot; (“12345, s0)
State Int ???
Int return State Int Int
236 (236, s0)
???
2009 5 31
18. State Int
String return State Int String
quot;ABCquot; (“ABC”, s0)
quot;12345quot; (“12345, s0)
State Int (v(s0), s(s0))
Int return State Int Int
236 (236, s0)
(v’(s0), s’(s0))
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19. • State s0
s0 v(s0)
s0 s(s0)
2
• a State (a, s0)
( return )
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20. • State
• State
State
• State
( >>= )
2009 5 31