@mixin mix1 {
position:relative;
width:100%;
height:auto;
}
.selector {
@include mix1;
}
%set1 {
position:relative;
width:100%;
height:auto;
}
.selector {
@extend %set1;
}
.someclass {
position:relative;
width:100%;
height:auto;
}
.selector {
@extend .someclass;
}