If you spent time around an engineer in the Eighties, you probably saw that person using a Hewlett-Packard scientific calculator. One of these sits next to a pad of graph paper and a few mechanical pencils in my eternal memory of Dad's briefcase.
Fun thing about HP calculators that's almost faded into history: They ran on reverse Polish notation. (This is a legitimate historical description, not an ethnic swipe.) Type in the first number, press enter, type in the second number, then press the key for the function (addition, division, whatever) to be performed. It allegedly simplified the calculator's programming, and it's certainly a logical way to do things, if not the most common one. Call it dogleg-1st notation.
Notation and proper sequencing seemed to be on the mind of BrtStlnd today, who responded to Elon Musk's lengthy word problem of a description of love with a pair of formulas that capture the spirit of a tech entrepreneur's nuptials:
Marriage is simple equation really:
φ = Love * (det(L)) > Perception of Virtue (PoV) ≈ Virtue
∑ Feelings ≠ Imported perceptions : PoV ∝ What lies within their heart
Addendum: Yes, they're still available.
Photo Credit: Henk Vermeulen