1+ operator
1.0? 
1.0  + 
1.0  - 
1.1 function
1.1 (expression)
1.1 constant
1.1 column-name
1.1 variable
1.1 special-register
1.1 (scalar-fullselect)
1.1 labeled-duration
1.1 case-expression
1.1 cast-specification
1.1 OLAP-specification
1.1 sequence-reference