D&D = Characters having Adventures.
Character = (fictional) Living Being. Life = Eventual Death.
Adventures = Excitement. Excitement = Risky. Risk = Eventual Loss.
Fun of Adventure = (Excitement)*1
Time remaining before Loss = (Remaining Lifespan)/(Risks Taken)
Therefore, if D&D = Fun, then Fun = Having Some Adventures, Then Losing Everything And Dying.
I'm not quite sure what to make of this.
I find other things to disagree with your proposal than what Umbran picks out about Life.
The final conclusion doesn't apply to me. I've not had PCs die and lose everything. I've had PCs die and come back. PCs lose everything and then get it back. I've had PCs retire and if they died, it was beyond the scope of game play and therefore not part of player consideration (ex. 500 years go by in the campaign world so we can start the next campaign).
Let's get to your variables, on which your conclusion relies:
Character = (fictional) Living Being.
--How about decision making agent that changes over time
Life = Eventual Death.
--Umbran quibbled this one. I don't think Living Being has to be part of the equation anyway
Adventures = Excitement.
--sure.
Excitement = Risky.
--probably true. But risk takes many forms, not just risk of life.
Risk = Eventual Loss.
--According to probability, not actually true. You can keep flipping a coing and it CAN keep turning up heads. Not a very high probability of that, but risk does not mean eventual loss, only potential loss.
Fun of Adventure = (Excitement)*1
--sure.
Time remaining before Loss = (Remaining Lifespan)/(Risks Taken)
--this is part of the falacy of risk. Loss isn't eventual, risk doesn't always mean loss of life. Loss doesn't even always mean end of game.
I'm not sure what your end goal is with this logic exercise. It looks like you're trying to drive a conclusion that D&D is about risking your life and eventually dying, and that's the defining component of its appeal.
That doesn't hold true for me, and I suspect it's not true for enough people that this doesn't even qualify as a decent generalization for which I'm merely an exception.
I have fun problem solving in D&D
I have fun socializing in D&D
I have fun portraying a character in D&D
I have fun building things (businesses, nations, organizations) in D&D
I have fun killing things in D&D
I have fun helping NPCs in D&D
I have fun being rewarded for my good deeds in D&D
I have fun outwitting the GM in D&D
I have fun escaping certain death in D&D