# -*- tcl -*- tcl.tk//DSL diagram//EN//1.0
proc mark {at args} {
    circle radius 2 at $at color red {*}$args
}
proc vector {p args} {
    mark $p {*}$args
    arrow from [0 0] to $p 
}

mark [0 0] "\[0 0\]" anchor ne
vector [50 20] "\[50 20\]" anchor sw