Hi, The following illustrates what looks like a bug in the compiler's handling of type propagation (bug disappears without the type declaration). CL-USER(25): (lisp-implementation-version) "1.1.0-dev-svn-14222M" "OpenJDK_64-Bit_Server_VM-Oracle_Corporation-1.7.0_03-b21)" "amd64-Linux-3.3.0-trunk-amd64)" CL-USER(26): (defun foo (a b) (declare (type (integer * 6488318769) b)) (max 1 (the (integer * 5711538578) a) b 2 1351352470)) FOO CL-USER(27): (foo 5711538444 6488318765) 6488318765 CL-USER(28): (compile 'foo) FOO NIL NIL CL-USER(29): (foo 5711538444 6488318765) 1351352470 -- Eric Marsden