Short answer: no.
Workaround: conceive some prefix to make a really unlikely name; something
like _my_internal_symbol_t_ or so.
Ameliorating circumstance: for the most part, symbolic variables are just
immutable place-holders, so it shouldn't matter who uses them. Probably the
most serious case is when your code interacts with user-supplied symbolic
expressions and you need to ensure that the variable you use is distinct
from the ones that occur in the supplied expressions. A prefix should
handle that (this is also how sage tries to avoid collisions when shipping
symbols to maxima: it prefixes them with _sage_var_). There is some global
state in the form of assumptions that can affect the meaning of symbols in
SR.
If you need multiple "unique" expressions you could go with a symbol
generating function. A very primitive one:
def gensym_generator():
i=1
while True:
yield SR.symbol("gensym%o"%i)
i+=1
gensym=gensym_generator().next
Every time you call gensym() you'll get a new symbol. Beware that these
symbols are not unique across sessions, so if you intend to use parallel
processing you already need to do something else (hash time in milliseconds
plus process ID together or something like that)
Also: don't overuse that kind of thing: symbolic variable are leaky (they
don't really get garbage collected).
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