license-id = <short form license identifier from https://spdx.org/spdx-specification-21-web-version#h.luq9dgcle9mo>
license-exception-id = <short form license exception identifier from https://spdx.org/spdx-specification-21-web-version#h.ruv3yl8g6czd>
simple-expression = license-id / license-id”+”
compound-expression = 1*1(simple-expression /
simple-expression "WITH" license-exception-id /
compound-expression "AND" compound-expression /
compound-expression "OR" compound-expression ) /
"(" compound-expression ")" )
license-expression = 1*1(simple-expression / compound-expression / UNLICENSED)