c:\Alex\ELENA\bin>elt
ELENA command line VM terminal 5.1.13 (C)2011-2020 by Alexei Rakov
ELENA VM 5.1.17 (C)2005-2020 by Alex Rakov
Initializing...
Done...

>f(s1,s2,sep){^ s1 + sep + sep + s2 };

>f("Rosetta","Code",":")
Rosetta::Code
>