I am trying to understand the meaning of the braces in the subscript of a variable. I've encountered it in a paper Distributional Reinforcement Learning with Quantile Regression, page 5
Does it mean "as long as the condition is met"? But what is then the alternative expression, when the condition is not met? Have a look at equation (12):
Do I read the equation 12 correctly:
- the $\theta_i$ becomes equal to its current value plus ( $\tau_i$ minus $\delta$ in cases where $r + \gamma z'$ is less than the current $\theta_i$ ), scaled by $\alpha$
Or do these { } braces have another interpretation? Are they used to denote a piece-wise function?