
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given that the function $f(x)$ satisfies $f(-x)=f(x)$ for all $x\in R$, and that for $x\geqslant 0$, $f(x+2)=f(x)$, with $f(x)=\log _{2}(x+1)$ when $x\in[0,2)$, determine the value of $f(-2014)+f(2015)$.

Present the answer in LaTex format: \boxed{Your answer}
user