1) defining the Ycombinator
{def Y {lambda {:f} {:f :f}}}

2) defining non recursive functions
2.1) factorial
{def almost-fac
 {lambda {:f :n}
  {if {= :n 1}
   then 1
   else {* :n {:f :f {- :n 1}}}}}}

2.2) fibonacci
{def almost-fibo
 {lambda {:f :n}
  {if {<   :n 2}
   then 1
   else {+ {:f :f {- :n 1}} {:f :f {- :n 2}}}}}}

3) testing
{{Y almost-fac} 6}
-> 720
{{Y almost-fibo} 8}
-> 34