(x OR y) AND z
[lex]    BRA "x" OR "y" KET AND "z"
[parse]  (AND (OR "x" "y") "z")
[gen]    ((x:(pos=1) OR y:(pos=2)) AND z:(pos=3))

# Incompatible; Xapian bails on the syntax error, we forge ahead.
(x OR y)) AND z
[lex]    BRA "x" OR "y" KET KET AND "z"
[parse]  (AND (OR "x" "y") "z")
[gen]    ((x:(pos=1) OR y:(pos=2)) AND z:(pos=3))
[xapian] (x:(pos=1) AND or:(pos=2) AND y:(pos=3) AND and:(pos=4) AND z:(pos=5))

# Empty subexpression after prefix
# Incompatible; Xapian treats as a syntax error.
prob:() AND x
[lex]    PREFIX/prob BRA KET AND "x"
[parse]  "x"
[gen]    x:(pos=1)
[xapian] (prob:(pos=1) AND and:(pos=2) AND x:(pos=3))

# Subqueries with same boolean prefix
lit:x lit:y
[lex]    PREFIX/lit "x" PREFIX/lit "y"
[parse]  (FILTER (OR (PREFIX/lit 'x') (PREFIX/lit 'y')))
[gen]    0 * (Lx OR Ly)

# Combining prob components
x -y lit:z
[lex]    "x" HATE "y" PREFIX/lit "z"
[parse]  (AND (AND "x" (FILTER (PREFIX/lit 'z'))) (NOT "y"))
[gen]    ((x:(pos=1) FILTER Lz) AND_NOT y:(pos=2))

x lit:z
[lex]    "x" PREFIX/lit "z"
[parse]  (AND "x" (FILTER (PREFIX/lit 'z')))
[gen]    (x:(pos=1) FILTER Lz)

-y lit:z
[lex]    HATE "y" PREFIX/lit "z"
[parse]  (AND (FILTER (PREFIX/lit 'z')) (NOT "y"))
[gen]    (0 * Lz AND_NOT y:(pos=1))

x -y
[lex]    "x" HATE "y"
[parse]  (AND "x" (NOT "y"))
[gen]    (x:(pos=1) AND_NOT y:(pos=2))