gvim has a option to search multiple characters with help of [ ] like
/delta_[123]_ can be used to search
delta_1_
delta_2_
delta_3_
But the same doesn't work for words like delta_one_,delta_two_,delta_three_
I tried
/delta_[onetwothree]_
/delta_[one|two|three]_
/delta_{one|two|three}_
