vu3rdd/hrtl-sol-notes-to-reader.txt

## hrtl-sol-notes-to-reader.txt
This companion volume to The Haskell Road to Logic, Math and Programming will enable you to check
your solutions to the exercises. It should be used wisely. You should only turn to the solution of an exercise
after you have tried to solve the exercise on your own. What the following pages do not provide is a shortcut to
understanding.
You don’t expect to improve your swimming or iceskating skills by watching swimming or iceskating contests
on TV. If you want to learn how to swim you must be willing to get wet. If you want to learn how to skate, you
must venture on the ice skating ring and take the risk of falling. Likewise, you can’t expect to improve your skills
in reasoning or programming by watching others reason or program. Just reading through the following pages, to
watch how the authors reason and program, is next to useless. You have to tackle the problems yourself, at the risk
of making mistakes, only using the solutions as checks on your understanding.
We can make this advice still more speciﬁc. When learning skil ls in formal reasoning it is easy to deceive
yourself into thinking you have thought hard enough. Therefore, a honest attempt to solve a problem should
always include a written account of how far you got. Thus, if you ﬁnd you cannot solve a problem, you should
have an attempted solution on paper. Your account should always end with “I can get this far, but then I am stuck
because . . . ” or “I follow the rules like on page . . . of the book, but then I get the wrong answer because . . . ”.
Proceeding like this, you will make very rapid progress. On the other hand, if you think you can disregard this
advice you might as well not bother with the book at all, for skills in formal reasoning and computation can only
be acquired by training, and without proper exercise you will never be any good at it.
You are completely free to do as you please, of course. Only don’t tell anyone you haven’t been warned.
	This companion volume to The Haskell Road to Logic, Math and Programming will enable you to check
	your solutions to the exercises. It should be used wisely. You should only turn to the solution of an exercise
	after you have tried to solve the exercise on your own. What the following pages do not provide is a shortcut to
	understanding.
	You don’t expect to improve your swimming or iceskating skills by watching swimming or iceskating contests
	on TV. If you want to learn how to swim you must be willing to get wet. If you want to learn how to skate, you
	must venture on the ice skating ring and take the risk of falling. Likewise, you can’t expect to improve your skills
	in reasoning or programming by watching others reason or program. Just reading through the following pages, to
	watch how the authors reason and program, is next to useless. You have to tackle the problems yourself, at the risk
	of making mistakes, only using the solutions as checks on your understanding.
	We can make this advice still more speciﬁc. When learning skil ls in formal reasoning it is easy to deceive
	yourself into thinking you have thought hard enough. Therefore, a honest attempt to solve a problem should
	always include a written account of how far you got. Thus, if you ﬁnd you cannot solve a problem, you should
	have an attempted solution on paper. Your account should always end with “I can get this far, but then I am stuck
	because . . . ” or “I follow the rules like on page . . . of the book, but then I get the wrong answer because . . . ”.
	Proceeding like this, you will make very rapid progress. On the other hand, if you think you can disregard this
	advice you might as well not bother with the book at all, for skills in formal reasoning and computation can only
	be acquired by training, and without proper exercise you will never be any good at it.
	You are completely free to do as you please, of course. Only don’t tell anyone you haven’t been warned.