@@ -105,15 +105,21 @@
 	char single_step();
 	void force(char c);
 }
 
+///
+/// Solver "Mountain":  be immovable like a mountain.
+///
 class 不動如山 : Solver
 {
 	this(in Game g) {}
 	char single_step() { return 'W'; }
 	void force(char c) {}
 }
 
+///
+/// Solver "Forest": shows contemplation.
+///
 class 徐如林 : Solver
 {
 	int wait_count = 0;
 	int choke_count = 0;
@@ -393,8 +399,11 @@
 		return (danger_ok ? [] : tryA()) ~ tryB() ~ tryC();
 	}
 }
 
+///
+/// Solver "Fire": in raiding and plundering other solvers, be like fire.
+///
 class 侵掠如火(SubSolver) : Solver
 {
 	// Parameters.
 	int            PredictFuture = 10;
@@ -600,8 +609,11 @@
 		return v;
 	}
 }
 
+///
+/// Solver "Wind": let your rapidity be that of the wind.
+/// 
 class 疾如風 : Solver
 {
 	Game g;
 	this(in Game g)