Roleset slow.01 Verbnet Class: 1 "(cause to) move more slowly":

Roles:

Arg0:causer of deceleration


Arg1:entity in motion

Examples:

transitive (-)
A reinstatement of the uptick rule for program traders would slow their activity considerably.
Arg0:	A reinstatement of the uptick rule for program traders
ArgM-MOD:	would
REL:	slow
Arg1:	their activity
ArgM-MNR:	considerably




ergative (-)
New loans continue *trace* to slow.
Arg1:	*trace* -> New loans
REL:	slow

Roleset slow.02 Verbnet Class: NONE "fall, decline":

Roles:

Arg1:Logical subject, patient, thing declining


Arg3:start point


Arg4:end point


ArgM-LOC:medium

Examples:

ergative with start point (-)
Activity continued *trace* to slow from the hectic pace set during the market's plunge late Friday and its rebound Monday, as players began to set their sights on events coming later this week.
Arg1:	Activity -> *trace*
REL:	slow
Arg3-from:	the hectic pace set during the market's plunge late Friday and its rebound Monday
ArgM-TMP:	as players began to set their sights on events coming later this week




ergative with end state (-)
While it has predicted that overall growth in unit sales of personal computers is slowing to about a 10% yearly rate...
Arg1:	overall growth in unit sales of personal computers
REL:	slowing
Arg4-to:	about a 10 % yearly rate

Roleset slow.03 Verbnet Class: NONE "(cause to) move more slowly":

Roles:

Arg0:causer of deceleration


Arg1:entity in motion

Examples:

transitive (-)
And the generally frail condition of Arizona's lenders means there is little capital available in the state *trace* to shore up the economy and slow down the slide.
Arg0:	*trace* little capital
REL:	[ slow] [ down]
Arg1:	the slide

I doubt the ergative construction can appear with 'slow down', but I could be wrong.