type Prio
class Trav a blk
data Term blk
data Prop blk
data OKVal
type OKHandle blk
type OKMeta blk
data Metavar a blk
data CTree blk
data SubConstraints blk
data PrioMeta blk
data Restore
type Undo
type RefCreateEnv blk
data Pair a b
class Refinable a blk
type BlkInfo blk
data MM a blk
type MetaEnv
data MB a blk
data PB blk
data QPB b blk
type HandleSol
type SRes
data Choice