My first name can be pronounced as "K S K".
The combinator X = λx.x K S K *1 is universal in the sense that all combinators can be constructed by X.
Actually, I is defined as X(XX)(XXX)z where z can be any term.
*1 As usual, you must recognize it as λx. ( ( ( x K ) S ) K ).
Keyword(s):
References: