Relational expressions

Syntax

RelationalExpression^β :
ShiftExpression
RelationalExpression^β > ShiftExpression
RelationalExpression^β < ShiftExpression
RelationalExpression^β <= ShiftExpression
RelationalExpression^β >= ShiftExpression
RelationalExpression^β as ShiftExpression
RelationalExpression^β is ShiftExpression
RelationalExpression^β is not ShiftExpression
[β = allowIn] RelationalExpression^β in ShiftExpression
[β = allowIn] RelationalExpression^β not in ShiftExpression