Problem with minuses in tensor library's ex_calc.mac

I've come across an issue that'll hopefully fix fairly easily: the functions 
covind and contind in ex_calc.mac (in the tensor share library) both get thrown 
by things with a minus operator.  I've had a quick look, and I reckon it'll fix 
the problem if you add the following lines:

Between lines 110 and 111:
else if op(t)="-" then covind(part(t,1))

Between lines 93 and 94:
else if op(t)="-" then contind(part(t,1))

I've added these changes on my copy, with no apparent ill effects so far...

The problem doesn't show up in ex_calc.dem, I think because some of the terms 
in all these examples are positive so it just ignores the anomalous result of 
the negative ones somehow.

Is it too late to get this changed for the new version?  Fingers crossed...!


               Josie