Print the translation of a form
:trans (list a b c)
:trans (caddr x)
:trans (cond (p q) (r))
ACL2 accepts user-level syntax as input, but translates it to an
internal syntax. This translation includes macroexpansion, replacing let forms by lambda expressions, quoting constants, and so on. See
term for relevant background.
Trans takes one argument, an alleged term in user syntax, and
translates it, expanding the macros in it completely. Either an error is
caused or the internal syntax for the term (representing its formal meaning)
is printed. We also print the ``output signature'' which indicates how many
results are returned and which are single-threaded objects. For example, a
term that returns one ordinary object (e.g., an object other than state or a user-defined single-threaded object (see defstobj)) has the
A term that returns the single-threaded object STATE has the output
and a term that returns four results might have the output signature
=> (MV $MEM * * STATE)
This signature indicates that the first result is the (user defined)
single-threaded object $MEM, that the next two results are ordinary, and
that the last result is STATE.
See trans! for a corresponding command that does not enforce
restrictions of single-threaded objects. See trans* for a command that
can show intermediate expansion results.
It is sometimes more convenient to use trans1 which is like trans
but which only does top-level macroexpansion.
For more, see term.