var v := struct;
v.+mem;

var d := dictionary;
d["a"] := 5;
d["b"] := 6;

print( d.exists( "a" ) );
print( d.exists( "c" ) );

v.mem := d;
var a := v.mem.exists( "a" );
print(a);
a := v.mem.exists( "c" );
print(a);