<human>: Question: What has been the result of attempts to connect Sumerian to other language groups?
Answer: Some authors have proposed that there may be evidence of a sub-stratum or add-stratum language for geographic features and various crafts and agricultural activities, called variously Proto-Euphratean or Proto Tigrean, but this is disputed by others.
 Is the question answered in a satisfactory fashion?

OPTIONS:
- yes
- no
<bot>: no