We have made a GNU APL reference card (and need a little help)

[Jeronimo Pellegrini via Bugs and suggestions for GNU APL]

Hello,

Lucas Vieira and I have made a reference card for GNU APL (which we hope
will be handy for beginners):

https://github.com/jpellegrini/gnu-apl-refcard

If there's anything important missing, please tell us!

There are, however, some system commands that we could not fully
understand:
)VALUES
]EXPECT
]LIB
]SIS
]SI
What do these do?

Thnak you!
Jerônimo Pellegrini