Why does it work ?

CREATE CURSOR zzz (dd n(5))
FOR i=1 TO 10
INSERT INTO zzz (dd) VALUES (i)
NEXT
INDEX on dd TO zzzi
SEEK 2
? FOUND() && .t.
SEEK "2 anything else"
? FOUND() && .t.
SEEK "2.0"
? FOUND() && .t.
USE IN zzz
RETURN

Search is successful in all cases. Though index is created on numeric field, search is done with character expression.
It MUST show a message about datatype mismatch. If not, it's terrible to change/define data types of searched
field or searched expression "on-the-fly".
SET ANSI, SET EXACT doesn't matter.
VFP9+SP2.