Appendices-Terms-l-value

An L-value is any variable that can be written to. Such variables can only be treated as l-values when they start a statement, either on their own or when declared. All initialized variables, whether or not they qualify as L-values, are implicitly R-values. Thus, once initialized, EVERY L-value is an R-value

var i% = 5 ' i% is an l-value
var F% = i% ' F% is an l-value, but i% isn't here as it doesn't start a line
i% = 343 ' i% is a l-value again
i% = 343 ^ 2 ' "343 ^ 2" isn't an l-value