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I'm doing a presentation in PowerPoint and use LaTeXiT to compile latex formulas into pdf and pasting them into the presentation. I want some formulas to appear chunk by chunk on the slides. Now I compile different chunks separately:

% Tex code for the first pdf
A &= \text{some expression}

% Tex code for the second pdf
A &= \text{some expression} \\&= \text{another expression}

The problem is that this way the formulas are sometimes compiled to be slightly different in size/spacing, and then I change slides the formulas visually jump.

A possible solution to this problem is to make the part that has not appeared yet transparent, so it will not be visible but is considered than calculating the sizes and spacings:

% Tex code for the first pdf
A &= \text{some expression} \transparent{0} \\&= \text{another expression}

% Tex code for the second pdf
A &= \text{some expression} \\&= \text{another expression}

But this is only a partial solution because for example, I can't add a comment in an underbrace this way:

% Tex code for the first pdf
A &= \underbrace{\text{some expression}}_{\text{comment}}

% Tex code for the second pdf
% Can't make underbrace transparent, have to remove it, the equation changes its size.
A &= \text{some expression}

So is there a way to compile a large equations kind of in chunks while accounting for all the parts that will appear in the equation later? What do you do in your slides?

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    Wrap all stuff you want to hide in \phantom{...}. This preserves the dimensions of the hidden content but does not display it. – Henri Menke Jun 19 '17 at 21:26
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    Most people here use beamer or texpower for this sort of thing. Are you using standalone [multi=minipage], or cropping the equations by hand? – John Kormylo Jun 19 '17 at 22:09
  • You might take a look at the the topmost related question: Problem with beamer's \pause in alignments. The first answer pretty much does what you want... – Skillmon likes topanswers.xyz Jun 20 '17 at 6:46
  • Why not cover the parts you want to be hidden by a white rectangle and remove these rectangles step by step? – samcarter_is_at_topanswers.xyz Nov 19 '17 at 13:53
  • The white rectangle approach is cool and works for most cases, but there is one that is not covered (it was not mentioned in the original question): say you derive a gradient of an expected value \nabla \mathbb{E} f(x) = \nabla \int p(x) f(x) d x = \int \nabla p(x) f(x) dx = ... I did this kind of derivations on the slides and with each step I created a new slide replacing the result of the previous step by the new step. I found only one way to align everything in this case - create each equation in independent pieces (one pdf image is the equality sign etc) and move/align them manually. – Bihaqo Nov 21 '17 at 6:03