Theorem nftru 1476

Description: The true constant has no free variables. (This can also be proven in one step with nfv 1538, but this proof does not use ax-17 1536.) (Contributed by Mario Carneiro, 6-Oct-2016.)

Assertion

Ref	Expression
nftru	⊢ Ⅎ𝑥⊤

Proof of Theorem nftru

Step	Hyp	Ref	Expression
1		tru 1367	. 2 ⊢ ⊤
2	1	nfth 1474	1 ⊢ Ⅎ𝑥⊤

Syntax hints:  ⊤wtru 1364  Ⅎwnf 1470

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-gen 1459

This theorem depends on definitions:  df-bi 117  df-tru 1366  df-nf 1471

This theorem is referenced by:  nfmo  2057  dvelimc  2353  nfralw  2526  nfralxy  2527  nfrexxy  2528  nfralya  2529  nfrexya  2530  nfreuxy  2664  nfsbc  2997  nfcsbw  3107  nfcsb  3108  nfiotaw  5196  nfriota  5855  nfixpxy  6734