id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
2	Check class instances against their definitions.	benl	benl	"We don't currently check whether a type class instance is valid wrt its definition. Unsafe program sometimes make it through the core type checker and sometimes not.

{{{T2-CheckInstance}}} contains an area function that has a larger closure than the definition, but it is silently accepted. I've seen other programs like this be caught by the core type checker.
"	defect	assigned	blocker	0.1.3	Type Inferencer	0.1.2