check if value in "columnA" = 5 OR value in "columnB" = "4" if yes get 1 otherwise 0 in GREL

Question

I'm trying to write GREL script like this:

... "newColumnName": "metric",

"columnInsertIndex": 2,

"baseColumnName": "ColumnA", ?

I do not know what to do next to declare another column (columnB).

With one column everything works f.ex.: if "columnA" = 5 OR "columnA" = "4"; 1,0 How about more columns?