1 # Evaluation semantics
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5 Assume we have given the following definition:
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10 Then the expression `f (f 13)` is evaluated in this way:
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14 f (13 + 1) because f 13 = 13 + 1
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16 14 + 1 because f 14 = 14 + 1
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20 ## Multiple equations
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22 If we have a more complicated function definition:
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26 fib n = fib (n-1) + fib (n-2)
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29 the expression `fib 4` is evaluated as
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33 fib (4-1) + fib (4-2) because fib 4 = fib (4-1) + fib (4-2)
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35 (fib (3-1) + fib (3-2)) + fib 2 because fib 3 = fib (3-1) + fib (3-2)
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36 fib 2 + fib 1 + fib 2 because fib 3 = fib (3-1) + fib (3-2)
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37 1 + fib 1 + fib 2 because fib 2 = 1
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38 1 + 1 + fib 2 because fib 1 = 1
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40 2 + 1 because fib 2 = 1
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