Well, NVL() appears to do what it should at least:
CREATE TABLE testtab (lvalue L null)
APPEND BLANK
REPLACE lvalue WITH .t.
APPEND BLANK
REPLACE lvalue WITH .f.
APPEND BLANK
REPLACE lvalue WITH null
GO top
SCAN NEXT 10
? lvalue
? ISNULL(lvalue)
? (NVL(lvalue,.f.))
?"-------------------"
endscan
.·*´¨)
.·`TCH
(..·*
010000110101001101101000011000010111001001110000010011110111001001000010011101010111001101110100
"When the debate is lost, slander becomes the tool of the loser." - Socrates
Vita contingit, Vive cum eo. (Life Happens, Live With it.)
"Life is not measured by the number of breaths we take, but by the moments that take our breath away." -- author unknown
"De omnibus dubitandum"