Sharing and extending SynthDefs

gistfile1.txt

fluid.defaults("colin.am", {
   gradeNames: ["flock.synth", "autoInit"],
   synthDef: {
       id: "carrier",
       ugen: "flock.ugen.sinOsc",
       freq: 440,
       mul: {
           id: "mod",
           ugen: "flock.ugen.sinOsc",
           rate: "control",
           freq: 1.0,
           mul: 0.25
       }
   }
});

fluid.defaults("mcld.amFm", {
   gradeNames: ["flock.synth", "colin.am", "autoInit"],
   synthDef: {
       add: {
           id: "modulator",
           ugen: "flock.ugen.sinOsc",
           freq: {
               ugen: "flock.ugen.mouse.cursor",
               rate: "control",
               add: 60,
               mul: 160
           }
       }
   }
});

var synth = mcld.amFm();