
function inc(x)         { return x+1; }
function dec(x)         { return x-1; }

function rtnBoolean()   { return true; }
function rtnString()    { return "foo"; }
function rtnInteger()   { return 57 }
function rtnDouble()    { return 5.7 }
function rtnUndef()     { return undefined }
function rtnNull()      { return null; }
//function rtnSymbol()    { return Symbol('foo') }
