trouble using predefined :prev_app tos definition

[njm2112]

In ./config/karabiner.edn, you define :prev_app (line 4) as a :tos definition, but I'm having trouble using it with your later-defined right_command re-mapping (lines 287-289):

➜  ~ goku
ERROR: invalid <to> in main section's Change right_command ...
Failed!

It seems that there's nothing defined for :application anywhere else in your config, but the <to> part of the rule invokes that at line 289: [:application :right_command nil {:alone :prev_app}].

Could you clarify what is intended by :application and why it might not be working for me?

[yqrashawn]

There's an application key on one of my keyboards. Maybe a filco minila?

Yes, found the keymap image. Beside the left arrow.