[edit] Case: general, special, degenerate, limiting

Questions to be addressed:

• Is 0 (a special case of) a number?
• Is a point (a special case of) a set?
• Is a scalar (a special case of) a vector?
• Is a number (a special case of) a function?
• Is a point (a special case of) a disk?
• Is the empty set (a special case of) an ellipse?
• Is a straight line (a special case of) a curve?
• Is time (a special case of) space?
• Is a linear equation (a special case of) quadratic equation?
• Is the instantaneous velocity (a special case of) average velocity?
• Is infinitesimal (a special case of) a number?
• Is infinity (a special case of) a number?

[edit] Miscellaneous questions (to be grouped somehow)

• Is a circle one-dimensional, two-dimensional or three-dimensional?