Using 'OR' with LogicLib ${If}

I can't find information on the useage of the LogicLib library, can someone point me in the right direction?

Anyway, what I want to know is that is it possible to us the operator 'OR' with the LogicLib ${If}? What I need is the following:

${If} "$var_INST" == "true"

;code

${Else}

;code

${EndIf}

But I need:

${If} "$var_INST" == "true" OR "$var_DB" == "true"

;code

${Else}

;code

${EndIf}

Is this possible?

${If} "$var_INST" == "true"

${OrIf} "$var_DB" == "true"

-Stu