https://drafts.csswg.org/css-grid/#valdef-grid-template-columns-flex
"When appearing outside a minmax() notation, implies an automatic minimum (i.e. ''minmax(auto, <flex>)'')."

It's not clear to me if what "implies" means, is it:

1. the computed value should be minmax(auto, <flex>)
   or
2. the computed value is <flex> but the used value for the min-sizing function is 'auto'