<s>
Program	O
Trace	O
Query	O
Language	O
(	O
PTQL	B-Language
)	O
is	O
a	O
language	O
based	O
on	O
relational	B-Application
queries	I-Application
over	O
program	O
traces	O
,	O
in	O
which	O
programmers	B-Application
can	O
write	O
expressive	O
,	O
declarative	O
queries	O
about	O
program	O
behavior	O
.	O
</s>
