Theorem nftru 1443

Description: The true constant has no free variables. (This can also be proven in one step with nfv 1509, but this proof does not use ax-17 1507.) (Contributed by Mario Carneiro, 6-Oct-2016.)

Assertion

Ref	Expression
nftru	|- F/ x T.

Proof of Theorem nftru

Step	Hyp	Ref	Expression
1		tru 1336	. 2 |- T.
2	1	nfth 1441	1 |- F/ x T.

Syntax hints:   T. wtru 1333   F/wnf 1437

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-gen 1426

This theorem depends on definitions:  df-bi 116  df-tru 1335  df-nf 1438

This theorem is referenced by:  nfmo  2020  dvelimc  2303  nfralxy  2474  nfrexxy  2475  nfralya  2476  nfrexya  2477  nfreuxy  2608  nfsbc  2933  nfcsb  3042  nfiotaw  5100  nfriota  5747  nfixpxy  6619