''flow_trysingle: <zone> | test/live/wait/fill :: <command if success> :: //<command if fail>//''

Will attempt to advance the groups in the named show zone, testing against the [[concepts:flow:flow conditions]] for that zone and the presence of an empty space at the start of the next zone; and running the attached commands depending on the result of the test. Running with a “test” flag will only run the test and the commends, “live” will also do the advance, “wait” will also put the zone into a waiting state, so that as and when the conditions arise that an advance is possible, it will happen automatically.

Using the "fill" flag works a bit differently - this checks to see if there is an empty group at the front of the named zone - and if so moves the group forward to fill this space.

In all cases, when a single zone is advanced, if successive groups behind it are in a waiting state, and all their conditions are met, they will also advance.

  * **zone** is the zone to try advancing
  * **test/live/wait/fill** are flags that sets the behaviour of the test as above - only one should be used
  * **command if success** is the command to be run if the test passes
  * **command if fail** is optional and will be run if the test fails (optional)