1. A method of extracting an extensible motif from a sequence, said method comprising: assigning on a computer a significance to an extensible motif within said sequence based upon a syntactic and statistical analysis; identifying an extensible motif having a significance that exceeds a predetermined threshold; and iterating said assigning said significance and said identifying said extensible motif, wherein said assigning said significance comprises assigning said significance based on a combination of saturation conditions at each iteration and monotonicity of probabilistic scores derived from the saturation conditions of said extensible motif.