Only need question 1.

a. Healthy plant growth follows from sufficient water. b. Increased availability of information is a necessary condition for further technological advances. c. Errors were introduced only if there was a modification of the program. d. Fuel savings implies good insulation or storm windows throughout. EXERCISES 2.1 1. Write the contrapositive of each statement in Exercise 5 of Section 1.1. 2. Write the converse of each statement in Exercise 5 of