Halliday & Matthiessen (2014: 721):
Relations of internal cause – cause in the sense of ‘x so I think/say y’ – are construed metaphorically by verbs of proving such as prove, show, demonstrate, argue, suggest, indicate, imply in ‘intensive identifying relational’ clauses:
||| The wide range of potential contributions by the RC has proven to be a bright spot || as we strive to match available resources to a demanding mission load, || and demonstrates clearly the enduring value and relevance of the citizen-soldier. |||
||| Further experiments proved [[[ that the dye lowered fertility in rats, || induced still-births || and even produced malformed and macerated foetuses]]] . |||
||| Large amounts of feldspar in a sandstone may imply rapid deposition and burial [[ before chemical weathering could decompose the feldspar]] , || or it might imply a cold climate [[ in which chemical weathering is very slow]] . |||