[TYPO3] What does this TS assignment mean: "2 < .1"

[Tapio Markula]

Ricardo Scachetti Pereira wrote:
>    Hi there again, folks,
> 
>    I'm looking at some TS templates inside static_templates table trying 
> to learn something useful and I came across some lines like this:
> 
> 2 < .1

all in object 1 will be copied for object 2
You need do define *only* such properties, which are
*different* compared with object 1.