What is the difference between a formal and informal proof? (Please give explanations)
A) A formal proof uses a table or a list of steps, whereas an informal proof uses paragraphs.
B) A formal proof provides the reasons for steps, whereas an informal proof does not.
C) A formal proof is much shorter, whereas an informal proof is longer.
D) A formal proof uses equations, whereas an informal proof only uses text.
What is formal and informal proof?