list.java

mmlang> :[define,list<=lst[[is,>-[count]==0]|
......>                    [is,[and,[head]?int],[tail]?list]]]
mmlang> ()[a,list]
==>true
mmlang> (1)[a,list]
==>true
mmlang> ('a')[a,list]
==>false
mmlang> (1;2;3;4;5;6)[a,list]
==>true
mmlang> (1;2;3;4;'b';6)[a,list]
==>false

  
// List[(Int,Str)*]
mmlang> :[define,list<=[[is,=(_)>-[count]==0]|               // |-lst (non-commutative additve group)
......>                 [[is,[head][a,int]];                 // ;-lst (non-commutative multiplicative monoid)
......>                  [is,[tail][head][a,str]];           
......>                  [is,[tail][tail][a,list]]]]]        
mmlang> (1;'a')[a,list]
==>true
mmlang> (1;2)[a,list]
==>false
mmlang> (1;2;'a')[a,list]
==>false
mmlang> (1;'a';2;'b')[a,list]
==>true
mmlang> (1;'a';2)[a,list]
==>false
mmlang> (1;'a';2;'b';3;'c')[a,list]
==>true