Examples:

Currently there are six parameters, initially all unfrozen.

XSPEC> freeze 2      ! Parameter 2 is frozen.

XSPEC> freeze 4-6    ! Parameters 4, 5, and 6 are frozen.

XSPEC> thaw 2 3-5    ! Parameters 2, 4, and 5 are thawed, parameter 3 is unaffected.

XSPEC> freeze        ! Parameters 3,4,5 are frozen (the last
                       range input by a freeze or thaw command).