step [, mode]
Enables stepping through LUX statements. Just before excution of each
selected statement, that statement and a prompt
are displayed. Strike a key to continue. The following keys have some
step to the next command at any level.
step to the next command at the current level.
step to the next command at a lower level.
enter and execute a command at the
abort the current calculation.
describe all keys with a side effect.
See also: trace