The tutorial http://ravichugh.github.io/sketch-n-sketch/tutorial/01.html describes v0.6.1. The current version v0.6.3 has a significantly different UI.

In general, it is possible to at least figure out where the described functionality now resides. However, there is no description for the new functionality, such as the new prominently located "Clean up" control.

Currently, Cozy will hang at the following state for a long time:

$ time cozy examples/select-flatmap.ds -t 10
Checking call legality...
Checking invariant preservation...
Done!
Adding query q...
STARTING IMPROVEMENT JOB q
updating with 1 new solutions
update order:
  --> q
considering update 1/1...
SOLUTION FOR q AT 0:00:00.037117 [size=74]
-------------------------------------

At the moment, synthesis can take "hints" about auxiliary functions, which can be used for synthesing the main one. For instance, this is a specification for tree flattening that takes an auxiliary function:

{ lseg(x1, s1) ** lseg(x2, s2) ** ret :-> x2 }
void lseg_append (loc x1, loc ret)
{ s =i s1 ++ s2 ; lseg(y, s) ** ret :-> y }

{ z :-> x ** tree(x, s) }
void flatten(loc z)
{ z :

Check that the software API is documented to a suitable level

Good: All functions/methods are documented including example inputs and outputs
OK: Core API functionality is documented