Haskell code for the Gentle Intro 98

• Section 2
• Section 2.1
• Section 2.1
• Section 2.3
• Sections 2.4, 2.5, 2.6
• Sections 2.5.1, 2.5.2
• Sections 3, 3.1
• Sections 3.2, 3.2.1, 3.2.2
• Sections 3.3, 3.4, 3.5
• Sections 4, 4.1, 4.2
• Sections 4.3, 4.4, 4.5, 4.6
• Section 5
• Section 6.1, 6.2, 6.3
• Section 7, 7.1, 7.2
• Section 7.3, 7.3, 7.5
• Section 8, 8.1, 8.2, 8.3
• Section 8.4
• Sections 9, 9.1, 9.2, 9.3
• Sections 10.1, 10.2, 10.3
• Section 10.4
• Section 11
• Section 11.1
• Sections 11.2, 11.3
• Sections 12, 12.1, 12.2, 12.3
• Sections 13, 13.1, 13.2, 13.3, 13.4, 13.5