LogicT

backtracking monad transformer with fair operations and pruning
tail
of a functional stream
control
, shift0
, control0
and
others in terms of shift
/reset
div/4
now reports finite
failures in more situations (e.g., when trying to divide any odd
number by two with the zero remainder).
(call/cc call/cc)
. Firstclass
continuations can be tricky, therefore, being formal helps.
eval
uating open code
lambda
as a library syntax
lookupdef
: Look up a value in alists of various formats
and handle the lookup failure