[susan53]

No. The second sentence is fine but the first is not possible. "As well" means "too" - it's a connective of addition, meaning that the two propositions are the same in some way. Again, you've eliminated the context - and it is the context which would disambiguate the meaning. Compare :

John stopped and Mary did as well. (John yes, Mary yes)
John stopped and so did Mary. (John yes, Mary yes)

John didn't stop but Mary did. (John no, Mary yes)
John stopped, but Mary didn't. (John yes, Mary no)


John didn't stop and Mary didn't either. (John no, Mary no)
John didn't stop and neither did Mary. (John no, Mary no)


So both "as well/so" and "either/neither" mean that the two were the same - but in the case of "as well/so" it's positive whereas in the case of "(not) either/ neither" it's negative.