[css-flexbox] Minor wording tweak to previous commit.

Author: fantasai

css-flexbox/Overview.html

@@ -1998,8 +1998,9 @@ <h2 class="heading settled heading" data-level=9 id=layout-algorithm><span class
 	<p>
 		As a special case for handling stretched <a data-link-type=dfn href=#flex-item title="flex items">flex items</a>,
 		if a <a data-link-type=dfn href=#single-line title=single-line>single-line</a> <a data-link-type=dfn href=#flex-container title="flex container">flex container</a> has a definite cross size,
-		any <a data-link-type=dfn href=#flex-item title="flex items">flex items</a> with <a class=css data-link-type=propdesc href=#propdef-align-self title=align-self>align-self: stretch</a> must also be treated as having a definite cross size
-		of the flex container’s inner cross size (clamped to the <a data-link-type=dfn href=#flex-item title="flex item">flex item</a>’s min and max <a data-link-type=dfn href=#cross-size title="cross size">cross size</a>).
+		the outer <a data-link-type=dfn href=#cross-size title="cross size">cross size</a> of any <a data-link-type=dfn href=#flex-item title="flex items">flex items</a> with <a class=css data-link-type=propdesc href=#propdef-align-self title=align-self>align-self: stretch</a>
+		is the flex container’s inner cross size (clamped to the <a data-link-type=dfn href=#flex-item title="flex item">flex item</a>’s min and max <a data-link-type=dfn href=#cross-size title="cross size">cross size</a>)
+		and is considered <a data-link-type=dfn href=#definite title=definite>definite</a>.
 
 	<p>
 		The following sections define the algorithm for laying out a flex container and its contents.

css-flexbox/Overview.src.html

@@ -1981,8 +1981,9 @@ <h2 id='layout-algorithm'>
 	<p>
 		As a special case for handling stretched <i>flex items</i>,
 		if a <i>single-line</i> <i>flex container</i> has a definite cross size,
-		any <i>flex items</i> with ''align-self: stretch'' must also be treated as having a definite cross size
-		of the flex container's inner cross size (clamped to the <i>flex item</i>&rsquo;s min and max <i>cross size</i>).
+		the outer <i>cross size</i> of any <i>flex items</i> with ''align-self: stretch''
+		is the flex container's inner cross size (clamped to the <i>flex item</i>’s min and max <i>cross size</i>)
+		and is considered <i>definite</i>.
 
 	<p>
 		The following sections define the algorithm for laying out a flex container and its contents.