The .drl file below produces
r3:one false
r2:one false
r1:one true
but only r1 is expected to fire.

Removing all "== true" is one way of showing the correct result.

declare Bool123
bool1 : boolean
bool2 : boolean
bool3 : boolean
end

declare Thing
name : String
bool123 : Bool123
end

rule kickOff
when
then
insert( new Thing( "one", new Bool123( true, false, false ) ) );
insert( new Thing( "two", new Bool123( false, false, false ) ) );
insert( new Thing( "three", new Bool123( false, false, false ) ) );
end

rule r1
when
$t: Thing( bool123.bool1 == true )
then
System.out.println( "r1:" + $t.getName() + " " + $t.getBool123().isBool1() );
end

rule r2
when
$t: Thing( bool123.bool2 == true )
then
System.out.println( "r2:" + $t.getName() + " " + $t.getBool123().isBool2() );
end

rule r3
when
$t: Thing( bool123.bool3 == true )
then
System.out.println( "r3:" + $t.getName() + " " + $t.getBool123().isBool3() );
end
~