Msb / Lsb

msb and lsb can be used in bit selection by []. msb means most significant bit of the operand. lsb means least significant bit of the operand, it is the same as 0.

module ModuleA {
    let a : logic<10> = 1;
    let _b: logic<10> = a[msb - 3:lsb];
    let _c: logic<10> = a[msb - 1:lsb + 1];
}