rule x when # ... bind 2 int and 2 long, making sure that # $int1 == 1 and $int3 == 65536... eval( $int1 == $long2 == $int3 == $long4 ) then // print all 4 values end Using dialect "java" this results in a syntax error, which is to be expected. Dialect "mvel" evaluates this to true for a surprising range of integer values. Here is a selection: 1 1 65536 1234567890 1 1 65536 424242 1 1 65536 65536 1 1 65536 4294967296 1 1 65536 65568 1 1 65536 65552 Is there any logic behind this? -W