[fib]

ps char b(0) [int l;char c;l=-1;while(c=b(++l)) MC c,1
return l
 ]

pl char b(0) [MC 13,1;MC 10,1;ps b
 ]

num char b(0);int v(0) [int k;v(0)=0
while(k<5) [if((b(k)<'0')+(b(k)>'9'))return k
v(0)=10*v(0)+b(k)-'0';++k]
return k
 ]

pn int n [MC ' ',1;MC n,14
 ]

atoi char b(0);int v(0) [int k,s;char c;s=1;c=b(0)
while((c==' ')+(c=='-')+(c=='+')) [
if(c=='-')s=-1;c=b(++k)]
k=k+num(b+k,v);v(0)=s*v(0);return k
 ]

gs char b(0) [return MC b,15
 ]

gn [char b(20);int v(0)
while(1) [gs b;if(atoi b,v)return v(0)
ps"number required "]
 ]

endlibrary

/* fib.ipl - tct - 4/12/9

/* time ./tinycx fib.ipl;echo

dpf int n,d,p [
 /* display proper fraction n/d as decimal number
 /* with p digit precision 
 int w
 w=10*n/d
 if (p) [
  MC w,14
  dpf 10*n%d,d,p-1 /* recursive call
  ]
 ]

fibf int f [
 if (f==0) return 1
 if (f==1) return 1
 return fibf(f-1)+fibf(f-2)
 ]

fib [
 pl "";ps "fib.ipl - tct - 4/12/9";pl ""
 int f,i,j
 pl "f? ";f=gn
 i=fibf(f);j=fibf(f-1)
 pl "";pn j/i;ps ".";dpf(j,i,14)
 pl ""
 pl "compared to ... 0.6180339887 4989484820 ..."
 pl ""
 ]