Is the remark column used for anything other than the final iteration?

[a-torgovitsky]

If not, then remove it and save the string as something else e.g. termination.lb and termination.ub Otherwise it's a bit odd to have empty strings for most entries in the table except the last once which has a very long string

[conroylau]

Done! Removed the remark column from the data frame df_bis and created two strings to store the message.

[a-torgovitsky]

Great I guess we should return just a single 2--dimensional vector with two strings: termination$ub termination$lb

[conroylau]

Good idea!

• For scalar-valued alpha, I changed it to a 2-dimension vector
• For vector-valued alpha, I changed it to a list, where each element of the list is a 2-dimensional vector