public Builder<T> R(
			final NonTerminal<T> start,
			final Consumer<? super Rule.Builder<T>> builder
		) {
			final var rb = new Rule.Builder<T>(start);
			builder.accept(rb);
			rules.add(rb.build());

			return this;
		}
Building a new rule for the CFG.

@param start the rule start
@param builder the rule builder
@return {@code this} builder for method chaining
jenetics.ext/src/main/java/io/jenetics/ext/grammar/Cfg.java