doc-isac/chuber/Functions.thy
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52106:7f3760f39bdc 52107:f8845fc8f38d
       
     1 theory Functions imports Main begin
       
     2 
       
     3 fun fib :: "nat \<Rightarrow> nat"
       
     4 where
       
     5 "fib 0 = 1"
       
     6 | "fib (Suc 0) = 1"
       
     7 | "fib (Suc (Suc n)) = fib n + fib (Suc n)"
       
     8 
       
     9 thm fib.simps
       
    10 
       
    11 (*"fib (Suc (Suc n))"*)
       
    12 
       
    13 lemma "fib 0 = 1"
       
    14 by simp
       
    15 lemma "fib (Suc 0) = 1"
       
    16 by simp
       
    17 lemma "fib (Suc (Suc (Suc 0))) = (Suc (Suc (Suc 0)))"
       
    18 by simp
       
    19 
       
    20 (*fun sep :: "’a \<Rightarrow> ’a list \<Rightarrow> ’a list"
       
    21 where
       
    22 "sep a (x#y#xs) = x # a # sep a (y # xs)"
       
    23 | "sep a xs
       
    24 = xs"*)
       
    25 
       
    26 
       
    27 end