function that builds an opAttribute based on between logic
bt(x, y)
# S4 method for integer
bt(x, y)
# S4 method for numeric
bt(x, y)
# S4 method for Date
bt(x, y)
the left side bound of the between logic This can either be an integer, numeric, or Date data type. Different data types will return the appropriate opAttribute type
the right side bound of the between logic. This can either be an integer, numeric, or Date data type. Different data types will return the appropriate opAttribute type