It used to, though. From the original Scheme paper: Note that in SCHEME, unlike MacLISP, the body of a LAMBDA expression is not an implicit PROGN.
R1RS does not permit it. And: In the the R1RS syntax BNF there is a (DEFINE (<identifier> <identifier list>) <form>) with one form. But later in the document it is a '<form list>'... Then the LAMBDA syntax has a BODY, but it is only a FORM...