Roleset alternate.01 Verbnet Class: 1 "switch between two possibilities":

Roles:

Arg0:causer of switch


Arg1:thing switching


Arg2:possibilities

Examples:

person: ns tense: ns aspect: progressive voice: active form: participle


agentive, merged possibilities (-)
The two leaders will meet on Dec. 2 and 3, *trace* alternating the two days of meetings between a U.S. and a Soviet naval vessel in the Mediterranean Sea.
Arg0:	*trace* -> The two leaders
REL:	alternating
Arg1:	the two days of meetings
Arg2-between:	a U.S. and a Soviet naval vessel in the Mediterranean Sea

person: ns tense: present aspect: ns voice: active form: gerund


this isn't even a verb! (-)
``Communism will reach its final stage of development in a feckless Russo -- corporation-socialist in form, nationalistic in content and Oriental in style -- that will puzzle the world with alternating feats of realism and recklessness...''
REL:	alternating
Arg1:	feats of realism and recklessness

Second example merges arg1 'thing switching' and arg2 'possibilities'. I don't think the possibilities can be separated into different args ('alternate from X to Y').