How can I change the default grouping on an operator without a built-in meaning?

I've created my own infix operator by defining `LeftArrow`.

    SetAttributes[LeftArrow, {NumericFunction, OneIdentity}]
    ex1_ \[LeftArrow] ex2_ := ex1 /. Rule[ex2[[1]], ex2[[2]]]

(I'm using the `Esc<-Esc` form of `LeftArrow` in the second line, but I'm not sure how to get it to cut and paste...)

When I use it, I need to string together applications like so:

    eqIld2 = (((((((eqIld \[LeftArrow] eqVrx) \[LeftArrow] eqVct) \[LeftArrow] eqIcr) \[LeftArrow] eqVct) \[LeftArrow] eqIcl) \[LeftArrow] eqVtx) \[LeftArrow] eqIin)

I'd like to be able to avoid all the parentheses, and to get the same result for the same input with the parentheses removed.

I don't see the default grouping for `LeftArrow` documented anywhere.  I've tried playing with various Attributes, but I can't find one that does what I want.  It looks like there's an `InfixNotation` that accepts options, but they aren't documented.

What's the trick?