{
    "name": "x3",
    "result_type": "RevCTMC[a]",
    "constraints": [ "Triplets[a,b]" ],
    "title": "Rate matrix on triplets/codon constructed from nucleotide rates",
    "call": "SModel.Codons.x3[a,submodel]",
    "args": [
        {
            "arg_name": "submodel",
            "arg_type": "RevCTMC[b]",
            "alphabet": "getNucleotides[@a]",
	    "description": "Nucleotide rates"
        },
        {
            "arg_name": "a",
            "arg_type": "a",
            "default_value": "getAlphabet",
	    "description": "The Triplets alphabet"
        }
    ],
    "description":"Rate matrix on triplets or codons constructed from a rate matrix on nucleotides.\n\nThus function can be used to build up triplet and codon models incrementally.",
    "examples": ["f81+x3+dNdS      // equivalent to mg94","gtr+x3"],
    "see": ["mg94","mg94_ext"]
}
