
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 $F$ is the focus of the parabola $C$: $x^{2}=2py(p > 0)$, a line passing through $F$ intersects the parabola $C$ at two distinct points $A(x_{1},y_{1})$ and $B(x_{2},y_{2})$, and $x_{1}x_{2}=-1$.

$(1)$ Find the equation of the parabola $C$.

$(2)$ Draw a perpendicular line from point $B$ to the $x$-axis, intersecting line $AO$ ($O$ is the origin) at point $D$. Draw a perpendicular line from point $A$ to line $DF$, and let its other intersection point with the parabola $C$ be $E$, with $G$ being the midpoint of $AE$. 

$\quad(1)$ Find the ordinate of point $D$.

$\quad(2)$ Find the range of values for $\dfrac {|GB|}{|DG|}$.

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