Wishlist: lambda with multi-expression body.

The Seasoned Schemer uses this on page 93.  So far I haven't seen it use
cond clauses with multiple consequent expressions.  Scheme allows cond
clauses to have zero or more consequent expressions.  It also has a
"(test => conseq)" syntax:

http://www.scheme.com/tspl3/control.html#./control:s13