/mi></msub><mo>−</mo><mi>b</mi><msub><mover accent="true"><mrow><mi mathvariant="bold">e</mi></mrow><mo>~</mo></mover><mi>α</mi></msub></mrow><annotation encoding="application/x-tex">c{\bold e}_x = a{\bold e}_\alpha - b\tilde{\bold e}_\alpha</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="strut" style="height:0.69444em;"></span><span class="strut bottom" style="height:0.84444em;vertical-align:-0.15em;"></span><span class="base displaystyle textstyle uncrampe