Add all the A tasks

Task/Anonymous-recursion/Fortran/anonymous-recursion.f

@@ -0,0 +1,18 @@
+integer function fib(n)
+  integer, intent(in) :: n
+  if (n < 0 ) then
+    write (*,*) 'Bad argument: fib(',n,')'
+    stop
+  else
+    fib = purefib(n)
+  end if
+contains
+  recursive pure integer function purefib(n) result(f)
+    integer, intent(in) :: n
+    if (n < 2 ) then
+      f = n
+    else
+      f = purefib(n-1) + purefib(n-2)
+    end if
+  end function purefib
+end function fib