@{
    var trueVar = true;
    var falseVar = false;
    var stringVar = "value";
    string nullVar = null;
}
<input checked="@true" />
<input checked="@trueVar" />
<input checked="@false" />
<input checked="@falseVar" />
<input checked="  @true    " />
<input checked="  @falseVar    " />
<input checked="    @stringVar: @trueVar   " />
<input checked="    value: @false   " />
<input checked="@true @trueVar" />
<input checked="   @falseVar  @true" />
<input checked="@null" />
<input checked="  @nullVar" />
<input checked="@nullVar   " />
<input checked="  @null @stringVar @trueVar" />