"Omit more multiplication signs" display flag

[christianp]

At the moment, an expression x*(y+1) is rendered in TeX as x × (y+1) - a multiplication sign is inserted, to make it clear x is not a function.

Should there be a display flag to omit this multiplication sign?

At the moment, the cases that can lead to a times symbol are:

• two digits next to each other, but from different things (e.g. 2*3)
• either argument is a factorial (e.g. x*y!)
• product of two names, at least one of which has more than one letter (e.g width*length)
• anything times a number (e.g. x*2)
• multiplication of a name by something in brackets (e.g. x*(y+1))
• anything times an op with lower precedence than multiplication, and the right-hand side starts with a digit (e.g. x * 2^y)

Of these, I can only think someone would want to omit the sign for the last three cases. Should it insert a space instead, or just nothing?

Here are options with space, and no space:

I think for the context this was reported in, there'd be no space.

[christianp]

Here's a much more compelling example, from Martin Jones: