OH … I forgot some of the NUMEROUS variants of the airplane that were tested. The Grumman X-29A was basically an F-16 with forward swept wings. The F-16XL was a ‘cranked arrow’ (much larger) wing that could carry all manner of weapons. And the NF-16 “Vista” is a variable stability demonstrator airplane that replaced the CALSPAN NF-33 which flew for 50 years in support of the US test pilot schools, et al. There were others:
See: en.wikipedia.org/wiki/General_Dynamics_F-16_Fighting_Falcon_variants